Strike Cheat Sheet

Quick-reference guide to tape reading codes, broker identification, and dilution probability.

0% Safe
0-5% Low Risk
10-20% Moderate
40-80% High Risk
90%+ Toxic
Broker / MMCodeTypeTypical BehaviorDilution %
Institutional
Morgan StanleyMSCOInstitutionalBlock prints only; rare in microcaps0%
Goldman SachsGSCOInstitutionalBlock prints; not dilution0%
JP MorganJPMXInstitutionalBlock trades; large sizes0%
BarclaysBARXInstitutionalBlock trades; rarely in micros0%
Merrill LynchMLCOInstitutionalBlock prints; no slicing0%
Retail & Options Market Makers
WolverineWOLV / WWMMOptions MMRetail-facing; neutral flow0-5%
Citadel SecuritiesCDELRetailRandom lot sizes; inconsistent timing; lifts ask; mixed flow0-5%
Virtu FinancialVIRTRetailRandom lot sizes; inconsistent; both sides0-5%
G1 Execution (Knight)G1X / NITERetailRandom prints; hit-or-miss behavior0-5%
SusquehannaSIGRetail/Options MMLarger prints; both sides; not robotic0-5%
MEMX ExchangeMEMXRetail ExchangeMixed flow; no consistent pattern0-5%
CBOE BYXBYXRetail ExchangeMixed prints; mixed sizes0-5%
CBOE BZXBZXRetail ExchangeStandard retail exchange flow0-5%
Algo & Mixed
Two Sigma2SIG / TWOSIGHF/AlgoHigh-frequency, but not dilution5-10%
EDGXEDGXRetail + Some AlgosMixed behavior; dilution only if robotic slicing appears10-20%
IEXIEXPassive Algo / Some ToxicHidden liquidity; midpoint pegging; slow slicing40-60%
CBOE (General)CBOEMixed / ToxicMixed behavior; dilution if robotic40-70%
EDGAEDGAAlgo / Toxic MMSmall-lot slicing; bid-hitting; repetitive cadence60-80%
Toxic Sellers
NYSE ArcaARCAToxic Seller / MMConstant selling; never lifting ask; slicing 50-500 share lots90%+
FINRA ADFFINRA / NQToxic Seller / MMRelentless bid-hitting; controlled cadence; major red flag95%+
Toxic Variants (Same Behavior)
FINRA ADF VariantADF / XADF / FINO / FINR / UNKToxic Seller / MM (FINRA Clone)Alternative labels for FINRA ADF; same behavior: relentless bid-hitting; controlled cadence95%+
NYSE Arca VariantARCX / ARCO / ARCDToxic Seller / MM (ARCA Clone)Alternative labels for NYSE Arca; constant selling; never lifting ask; sliced 50-500 share lots90%+
EDGA / EDGX VariantsEDGM / EDGD / XEDGAlgo / Toxic MM VariantAlt codes for EDGA/EDGX; if robotic small-lot slicing and bid-hitting, treat as dilution60-80%
Retail - You
Apex ClearingAPEX / CDEL / VIRTRetail Clearing (Webull, Public, Ally, Moomoo)Mostly internalized through Citadel/Virtu; inconsistent lot sizes; retail behavior0-5%
Robinhood ClearingRHS / CDEL / VIRTRetail InternalizerRetail prints routed to Citadel/Virtu; rarely shows distinct RHS L2 code0-5%
Clearing Broker SvcsCBSXRetail / Prop HybridChicago-based exchange; mixed prints; not dilution0-5%
Penson FinancialPNSNRetail Clearing (rare today)Legacy routing; mainly shows as CDEL/VIRT in modern systems0-5%
Apex ProAPXP / APEX PROInstitutional/Prop InternalizerLarger, cleaner prints; non-dilutive0-5%
Clear StreetCSTIProp + Retail PrimeNewer prime broker; clean prints; not used for toxic dumping0-5%
DriveWealthDRVWRetail (International RH)Small-lot retail prints; inconsistent patterns0-5%
ETRADE ClearingETCLInternal Retail ClearingPrints ultimately show through CDEL/G1X/SIG0-5%
TD AmeritradeTDAC / SCHWRetail ClearingPrints show through SIG/CDEL; not dilution0-5%
Direct Access Brokers
Cobra TradingARCA / EDGX / EDGA / MEMX / NSDQ / BATSDMA Retail/PropDirect ECN routing; larger lots; aggressive but not robotic0-10%
CenterPoint SecuritiesARCA / EDGX / NSDQ / BATS / IEXDMA Prop/RetailLots of liquidity taking; inconsistent cadence; not dilution0%
Guardian TradingARCA / EDGX / MEMX / BATSDMA RetailInconsistent prints; larger lots; human behavior0%
SpeedTraderARCA / NSDQ / EDGX / IEX / BATSDMA Retail/PropAggressive entries; non-robotic; scalper-style flow0%
SuccessTraderARCA / NSDQ / EDGX / IEX / MEMXDMA RetailScalper/momentum flow; fast prints; irregular sizes0%
Venom/LightspeedARCA / EDGX / NSDQ / IEXDMA RetailFast direct routing; no robotic patterns0%
TradeZero ProARCA / EDGX / NSDQDMA HybridSome internalization but not toxic; inconsistent cadence0-5%
ClearStreet PrimeCSTIPrime BrokerLarger block prints; institutional-like; not dilution0%
Alternate & Rare Routes (Non-Toxic)
NASDAQ PrimaryNSDQ / NASDAQ / XNASPrimary ExchangeRetail + DMA; real NBBO source; irregular cadence; not used for toxic dumping0-5%
NASDAQ BXBX / NQBX / XBXSecondary ExchangeRetail + prop DMA; occasional prints; not a dilution route0-10%
NASDAQ PSXPSX / XPSXSecondary ExchangePassive/alt Nasdaq book; some hidden liquidity; not toxic0-5%
NYSE AmericanXASE / ASEExchange (AMEX)Occasional prints; legacy book; non-toxic; rarely used in microcap dumps0-5%
Philadelphia ExchangeXPHL / PHLXExchange (PHLX)Rare equity prints tied to options hedging; not a dilution source0-10%
Chicago Stock ExchangeXCHI / CHXExchange (CHX)Slow legacy book; occasional odd lots; not used for toxic selling0-10%
International SecuritiesISE / XISXOptions / Alt VenueMostly options-related; equity prints are rare and non-toxic0%
CBOE BYX VariantBATY / BYY-Book for CBOE; Retail/DMAMirrors BYX/BZX behavior; regular retail/DMA flow; not dilution0-5%
NYSE Listed BaseNYS / XNYSPrimary NYSE BookNormal exchange prints; institutional + retail; not a dilution route0-5%
*click to expand each one*
No filings match your search.
FilingWhy Filed?When Filed?How to Interpret?Price ImpactLink
Dilution / Prospectus Filings
S-1/F-1IPOMonths prior to pricing of IPOFirst page will say initial public offeringNoneSEC
Explanation: Prospectus required for the registration of shares initially issued and sold in an IPO
S-1/F-1Follow-on / Secondary OfferingUsually less than one month before pricing dateFiling will specify a maximum $ amount being offered and placeholders for # of shares and priceMediumSEC
Explanation: Companies may use S-1 instead of a shelf (S-3) to register a follow-on/secondary public offering, which would normally result in a price decline depending on the pricing and offering terms. If no PR prior to filing, then the market will interpret this as new information and price will decline. Market will fully price in the offering once PR of pricing is announced.
S-1/F-1Resale — register previously restricted shares, shares underlying warrants/convertible securities, equity line agreementsAnytime, or contractually within time period specified in the registration rights for any private placementFiling will specify exactly which shares, who's selling, and how many shares are being registeredNone-LowSEC
Explanation: Restricted securities need registration before it can be sold to public without rule 144 restrictions. Minimal impact on initial filing because requires EFFECT before shares are officially registered and can be sold. Once effective, may have material impact if unlocked shares greatly exceed current trading float or after a short squeeze.
S-1/F-1/AAmend prior filingAfter initial filingCheck which filing it's linked to by clicking the file numberNoneSEC
Explanation: Original filing may need amendments for additional disclosures, or finalizing exhibits such as underwriting agreements, documents detailing warrants/convertible terms, consent of accountant & counsel before receiving EFFECT
EFFECTFiled when SEC has officially finished review of filingUsually within one month of S-1/F-1, S-3/F-3, F-10, but longer when co is smaller, has complex financials, or foreign. All EFFECTs are bulk publicly disclosed at 6:00AM daily.Check which filing it's linked to by clicking the file numberLow-MedSEC
Explanation: EFFECT is required before an S-1/F-1 related offering can be priced, a shelf can be used, or resale shares be fully registered and sold. Will have biggest market impact when market is unsure of exact date of pricing for small cap discounted S-1 offering, since public disclosure of EFFECT for S-1/F-1 offering means pricing is imminent.
S-1/F-1MEFUp-size prior offeringAfter EFFECT and shortly before pricingCheck which filing it's linked to by clicking the file numberLow-MedSEC
Explanation: Co can decide to upsize up to 20% more than max $ amount previously specified even after receiving EFFECT. Some instant impact potential if market is anticipating a discounted offering but unsure of timing; the filing signals co has received EFFECT and pricing announcement is imminent.
424B4Final prospectus disclosing offering detailsAfter pricing of IPO or S-1/F-1 related offeringCheck which filing it's linked to by clicking the file numberNoneSEC
Explanation: Final prospectus supplement for the S-1/F-1 containing the pricing details and shares issued. No impact because pricing PR would have been released before this.
S-3/F-3/F-10ShelfAnytime the company plans to raise funds over a period of three yearsWill state a max $ amount being registered and the types of securities issuableNone-LowSEC
Explanation: An effective shelf allows the co to offer at anytime within the next three years up to the shelf $ amount, unless subject to $ limits imposed by the baby shelf rule. No immediate impact because initial filing can't be used until receiving EFFECT. Sometimes attached with ATM.
S-3/F-3/F-10Resale — register previously restricted shares, shares underlying warrants/convertible securities, equity line agreementsAnytime, or contractually within time period specified in the registration rights for any private placementFiling will specify exactly which shares, who's selling, and how many shares are being registeredNone-LowSEC
Explanation: Restricted securities need registration before can be sold to public without rule 144 restrictions. Minimal impact on initial filing because requires EFFECT before shares are officially registered and can be sold. Once effective, may have material impact if unlocked shares greatly exceed current trading float or after a short squeeze.
S-3/F-3MEFUpsize prior shelfAnytime after EFFECT on shelfCheck which filing it's linked to by clicking the file numberLow-MedSEC
Explanation: Co can decide to upsize up to 20% more than max $ amount previously specified on the shelf even after receiving EFFECT. May have price impact because it signals that the company intends to use the shelf imminently, since the co wouldn't upsize the shelf unless it plans to use it soon.
S-3/F-3ASRAutomatic shelf registrationAvailable to "Well-Known, Seasoned Issuers" (WKSI) — exceeded $700m float in last 60 days or issued $1B+ non-convertible securities in last 3 yearsWill be blank for $ amount (unless contains ATM) and state which types of securities issuableNone-LowSEC
Explanation: Called automatic because it receives EFFECT automatically at the time of filing. A company can use the shelf immediately and offer right away. If they offer right away, it can have material price impact. There is also no limit on the $ amount for this shelf. Sometimes attached with ATM.
S-3/F-3ASRResale — register previously restricted shares, shares underlying warrants/convertible securities, equity line agreementsAnytime, or contractually within time period specified in the registration rights for any private placementFiling will specify exactly which shares, who's selling, and how many shares are being registeredNone-LowSEC
Explanation: ASR can also be used for resale purposes as long as the company meets the WKSI criteria, meaning shares are registered the moment it's filed without need for additional wait period for EFFECT.
424B5ATM (At-the-Market Offering)Anytime after EFFECT on shelfFirst page will state max $ issuable from time to time and mention "at the market offering" or "equity distribution agreement"None-MedSEC
Explanation: Once filed, co can issue shares on the open market anytime up to the $ amount. Usually filed throughout course of business so market will not know if the company will use immediately. Normally no market impact on filing. Will have impact if it's more obvious co will use immediately, such as filing after a big run up and needs cash badly. Sometimes filed with 424B3.
424B5Final prospectus disclosing offering detailsShortly after pricing PRFiling will specify shares issued and price/share inline with PRNoneSEC
Explanation: Prospectus supplement filed to disclose an offering was completed and linked to the shelf it was issued with through the same file number. No impact because the PR would be out first, unless placeholder 424B5 was filed before PR.
424B5Register shares underlying warrants/convertible securitiesAnytime, or contractually within time period specified in registration rightsFiling will specify which warrants or convertible securities are being registeredNoneSEC
Explanation: A 424B5 can also be used to register shares underlying warrants/convertible securities, which will reduce capacity room on the shelf. No impact most of the time unless market is highly short sale constrained.
424B3Filed after resale registration receives EFFECTAfter resale registration receives EFFECTFirst page will match the original resale registration filingNone-LowSEC
Explanation: Customary filing after resale registration receives EFFECT. Shares officially registered after this and may have material impact over time if unlocked shares greatly exceed current trading float or after a short squeeze.
424B3Amend prior filingWhen there is additional material disclosure requiredFirst page will mention amendmentNoneSEC
Explanation: Usually filed if new material development occurs while prior S-1/F-1 filing is still active. No impact because it will usually contain the same disclosure as the 8-K.
RWWithdrawal of registration filingAfter initial filing and whenever co wants to withdraw itCheck which filing it's linked to by clicking the file numberLow-MedSEC
Explanation: Co may decide to withdraw a prior registration such as S-1 or S-3. If the market was already partially pricing in an offering, then the public disclosure of RW may cause a pop because it signals that the company is cancelling the offering. Less impact if RW for resale.
Financials
10-QQuarterly financialsDeadline 45 days after quarter end for <$75m float, 40 days for others. 99% filed after earnings PR.N/ANone-LowSEC
Explanation: Discloses updated financials and any additional required disclosures since last quarter. Only immediate impact if earnings PR not released yet and 10-Q filed beforehand with financials materially different from market expectations. Quarterly financials for foreign firms not required but may be disclosed in form 6-K.
10-KAnnual financialsDeadline 90 days after fiscal year end for <$75m float, 75 days for $75-700m, 60 days for >$700m. 99% filed after earnings PR.N/ANone-LowSEC
Explanation: Discloses updated financials and any additional required disclosures. Only immediate impact if earnings PR not released yet and 10-K filed beforehand with financials materially different from market expectations.
20-FAnnual financials for foreign coDeadline 4 months after year endN/ANone-LowSEC
Explanation: Discloses updated financials and any additional required disclosures. Only immediate impact if earnings PR not released yet and 20-F filed beforehand with financials materially different from market expectations.
40-FAnnual financials for Canadian coDue same day as issuer's annual report is due in CanadaN/ANoneSEC
Explanation: Canadian version of 20-F.
Material Disclosures
8-KDisclosure for material event/changeWithin 4 days of the event. 99% of time PR before 8-K, or no PR.Filing will have categories describing the type of event and details. If filed with PR, exhibits will contain PR.None-HighSEC
Explanation: Main categories: Earnings, business updates, listing status, M&A activity, acquisitions/dispositions, changes in control or management, change in auditors, securities issuances, and bankruptcies/restructuring. If the filing is material and publicly released before the PR, then will move markets depending on severity. See attached exhibits for raw documents of material contracts, purchase agreements, and other legal documents.
6-KDisclosure for material event/change for foreign firm"Promptly" after the event. 99% of time PR before 6-K, or no PR.Filing will have categories describing the type of event and details. If filed with PR, exhibits will contain PR.None-HighSEC
Explanation: If the filing is material and publicly released before the PR, then will move markets depending on severity. See attached exhibits for raw documents of material contracts, purchase agreements, and other legal documents.
Ownership
SC 13DInitial ownership disclosure for activist stakesWithin 10 days of acquisition >5% o/sFiling will state who filed, how many shares or derivatives owned, and % of ownershipNone-MedSEC
Explanation: Main difference between 13D and 13G is purpose of stake — 13D for those with intent on having influence over the company, 13G for passive investors. May have positive price impact if a prominent investor acquires a large activist stake or significant % of the float. Filing will also disclose why the investor bought and each transaction.
SC 13GInitial ownership disclosure for passive stakesWithin 45 days of acquisition >5% o/s, within 10 days for >10%Filing will state who filed, how many shares or derivatives owned, and % of ownershipNone-MedSEC
Explanation: May have positive price impact if a prominent investor acquires a large stake or significant % of the float.
SC 13D/ADisclose ownership changes for activist stakesWithin 2 days whenever ownership changes >1% of o/s or falling below 5%Filing will state who filed, new # of shares or derivatives owned, and % of ownershipNone-LowSEC
Explanation: May have positive/negative price impact depending on magnitude of change and which investor bought/sold. Will also disclose each transaction of the investor.
SC 13G/ADisclose ownership changes for passive stakesAll filers: once a year within 45 days after year end if any changes. Within 2 days of falling below 5%. QIIs: within 10 days after end of first month when >10%. Passive: within 2 days when going over 10%.Filing will state who filed, new # of shares or derivatives owned, and % of ownershipNone-LowSEC
Explanation: May have positive/negative price impact depending on magnitude of change and which investor bought/sold.
Form 3Initial filing of insiderWithin 10 days of becoming an insiderFiling will state who filed, # of shares/derivatives owned, and position of personNoneSEC
Explanation: Only filed once when a person becomes an officer, even if holding 0 shares.
Form 4Transaction of insiderWithin 2 days of transactionFiling will state who filed, date of transaction, # of shares/derivatives transacted at what price, and position of personNone-MedSEC
Explanation: If an important insider purchases or sells a large stake, market may react to it as positive/negative signal. Make sure to read footnotes as to how the shares were purchased or sold. Sometimes part of automated plan.
Form 5Omitted transaction of insiderWithin 45 days of year endFiling will state who filed, date of transaction, # of shares/derivatives transacted at what price, and position of personNoneSEC
Explanation: Only filed if an earlier transaction was not reported.
Proxies
PRE 14APreliminary ProxyAt least 10 calendar days prior to when the definitive proxy is sent outProxy will mention it's preliminary and contain the list of proposals that require a shareholder voteNoneSEC
Explanation: Only required for non-annual shareholder meetings, so usually special meetings for one-off items such as reverse splits, authorized share increases etc.
DEF 14ADefinitive ProxyAfter the preliminary proxy, or within 120 days after year end for the annual meeting proxyProxy will contain the list of proposals that require a shareholder voteNoneSEC
Explanation: Most companies have one standard annual shareholder meeting per year so they will have at least one DEF 14A per year. Proxies can also contain information not found in other filings, such as major shareholders, insider ownership, and executive compensation schemes.
DEFM14AProxy related to mergerAfter merger is announcedProxy will contain merger related proposalsNoneSEC
Explanation: Proxy specifically for voting on proposals related to merger. Will contain details related to merger structure and the parties involved with the merger.
PREC14A / PRRN14A / DFAN14AProxies filed during proxy warWhen a shareholder group has their own proposals or board nominees different from incumbent boardProxy will contain activist proposalsNone-LowSEC
Explanation: Depending on what the activist is pushing for, may have material impact if trying to push for sale or some immediate value realization.
Other Less Relevant Forms
S-4/F-4Registration for shares issued in connection with a mergerAfter a merger is announcedFiling will contain which shares are being registered and merger detailsNoneSEC
Explanation: Filed when shares that are issued to a merger target need to be registered. Also filed for exchange offers.
425Additional disclosure related to mergerAfter S-4 is filed, when new information needs to be disclosed related to the mergerWill contain the disclosure items, should match accompanying 8-KNoneSEC
Explanation: Will be close to identical to the 8-K disclosing any material event.
1-AProspectus for offering under Regulation A+Anytime co wants to raise funds from public under Reg A+ rulesLooks similar to IPO S-1 for exhibit PART II of filingNoneSEC
Explanation: Regulation A+ is a legal process of fundraising similar to crowdfunding. Allows more solicitation of IPO demand through social media and other means not allowed in S-1 IPO. Historically, very low quality companies IPO through this path.
1-U / 1-K / 1-SARegulation A+ equivalents of 8-K, 10-K, 10-QWithin 4 days for 1-U, within 120 days of year end for 1-K, within 90 days of mid year for 1-SAN/ANone
Explanation: Same as equivalents. Regulation A+ companies only require one semi-annual (1-SA) report instead of 10-Q each quarter. Most Reg A+ companies convert to normal reporting company after IPO.
13F-HRDisclose positions of institutional investor with >$100m AUMWithin 45 days of each quarter endFiling will list each position of the investorNone-LowSEC
Explanation: Required disclosure filed by investment funds greater than $100m AUM. May have market impact if a prominent investor adjusts its stake in a company, if not already disclosed in 13G/D.
S-8Register shares given in employee benefit plansAnytimeFiling will mention shares and options issued as part of employee benefit planNoneSEC
Explanation: Special registration for shares given in employee benefit plans, less disclosures in S-8 so faster to file. No impact as these shares are usually sold in small amounts and over a long period of time.
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