Is dark pool data real time?
By Faizan Ahmad. Updated .
No. Dark pool prints are after-the-fact reports by nature. Off-exchange trades are reported to FINRA after they execute, normally within 10 seconds, but the biggest ones (negotiated blocks, average-price and portfolio trades) are often reported late, sometimes hours later, at a price from earlier in the day, flagged with late or out-of-sequence condition codes. Tradytics shows prints within about 15 minutes of their report, which fits what dark pool data is good for: finding levels where size accumulated over days, not catching the second a trade happened.
How fast do off-exchange trades have to be reported?
When a stock trades anywhere other than an exchange, in a dark pool or with a wholesaler, the broker-dealer involved reports it to one of FINRA's trade reporting facilities (TRFs). From there it goes out on the same consolidated tape that carries exchange trades. FINRA's rule for regular hours is "as soon as practicable but no later than 10 seconds after execution," and any trade reported later than that must be designated late. If the firm doesn't add the late flag, the facility adds it.
| When the trade happened (ET) | Reporting deadline | Flag |
|---|---|---|
| 9:30 AM to 4:00 PM | 10 seconds | Late flag if reported after 10 seconds |
| 8:00 AM to 9:30 AM, 4:00 PM to 8:00 PM | 10 seconds | Outside-hours flag, or its late version after 10 seconds |
| Midnight to 8:00 AM | By 8:15 AM the same day | Outside-hours flag |
| 8:00 PM to midnight, or a non-business day | Next business day by 8:15 AM, as an "as/of" trade | Outside-hours flag |
The 8:00 AM line and the 8:15 AM deadlines come from temporary relief in FINRA Rule 6380A that lasts until December 31, 2027 at the latest; the base rule starts the 10-second clock at 4:00 AM. Most reports are much faster than the limit: in a week of June 2014, FINRA found 97.3% of off-exchange trades in listed stocks were reported within two seconds. The slow ones are the ones traders care about most.
Why do the biggest dark pool prints show up late?
Big off-exchange trades are often negotiated. A fund agrees with a bank to trade a block at the day's average price, at the closing price, or as part of a basket of many stocks. The price comes from a formula or an earlier moment, and the trade reaches the tape when the deal is booked. FINRA has separate flags for this: one for late reports, one for a "prior reference price" (the report must carry both the execution time and the earlier reference time) and one for average-price and other formula-priced trades. Trades with these flags generally don't update the stock's last sale price, because they don't reflect the market at that moment.
On October 30, 2026, a 3,684,100-share SPY dark pool print worth $2.84B was reported at 4:28 PM ET at $769.559, about $12 above where SPY closed ($757.12) and right at the prior day's close: a late, previously agreed trade, not a fresh bet at that price. Seeing it the instant it was reported would not have helped anyone. It was a receipt for a deal done earlier, not an order still working. The full anatomy of prints like this is in what a late or out-of-sequence print is.
The three clocks behind every print
| Clock | What it measures | Typical gap |
|---|---|---|
| Execution time | When the trade happened or was agreed | None |
| Report time | When the broker reported it to FINRA | Seconds for most trades; minutes to hours for late and reference-price trades |
| Display time | When it appears in your data tool | On Tradytics, within about 15 minutes of the report |
FINRA's own summary data runs on slower clocks. Its daily short sale volume files are posted by 6:00 PM ET on the trade date. Its weekly volume for each dark pool (each alternative trading system, or ATS) comes out no earlier than two weeks after the week ends for Tier 1 stocks, the big liquid names, and four weeks for the rest. So "delayed dark pool data" can mean a 15-minute display window or a month-old venue breakdown, and they are not the same thing.
Does a 15-minute delay matter?
Not for the way dark pool data is used. Dark pool data is read for levels (where size accumulated over days), not for the second a print happened, so a 15-minute window changes nothing about the levels, which are built from 10 sessions of prints. On October 30, 2026, SPY's biggest dark pool level sat at $769.48: $20.78B in 155 off-exchange prints over the last 10 sessions, more than three times the $6.37B of dark pool and block prints SPY sees on a usual day. One more print arriving a few minutes later doesn't move a level built from 155 of them.
Speed would only matter if you tried to trade the print itself, and that is what dark pool data is worst at. You don't know when the deal was struck, what reference price it used, or which side started it. How to read dark pool prints and what dark pool levels are cover the reading that does work.
Options flow is a different story
Listed options trade on exchanges, and every trade goes out on OPRA, the consolidated options tape. There is no off-exchange reporting step like the one stocks have, which is why options flow on Tradytics' Live and Pro plans is live to the second while dark pool prints are not. More in are there dark pools for options.
How to see it on Tradytics
The dark pool page lists off-exchange prints and exchange blocks with their time, price, shares, value, venue and sale condition, so late and reference-price prints can be spotted. For one stock, open its dark pool page, for example SPY, for prints today, the 10-session levels and how much traded against a usual day. On Live and Pro, prints appear within about 15 minutes of their report; the Free plan shows yesterday's session.
Common questions
Can anyone see dark pool trades the moment they happen?
No. Until a broker reports the trade, nobody outside the deal knows it happened. Most reports arrive within seconds, but late and reference-price trades can surface hours after they were agreed.
Is FINRA's dark pool data delayed?
The trade-by-trade tape follows the reporting rules above. What's delayed is FINRA's breakdown by venue: weekly volume for each ATS is published two to four weeks after the week ends.
Why do some dark pool prints appear after 4:00 PM?
Some are after-hours trades, some are late reports of trades done during the day, and some are trades priced at the closing price, which can only be booked once the close is known.
Does the Tradytics Free plan show dark pool prints?
Yes, for yesterday's session. Live ($39 a month) and Pro ($69 a month) show today's prints within about 15 minutes of their report.
Sources
- FINRA Rule 6380A, Transaction Reporting: the 10-second deadline, the late designation, outside-hours deadlines and the temporary 8:15 AM relief.
- FINRA, Trade Report Modifiers: the late, prior reference price and average-price flags and whether each updates the last sale.
- FINRA Rule 6110: the two-week and four-week delays on weekly ATS volume.
- FINRA Regulatory Notice 14-46: the 2014 reporting-speed data and how off-exchange trades reach the consolidated tape.
- FINRA, Daily Short Sale Volume Files: posted by 6:00 PM ET on the trade date.
- Dark pool and block prints on 2026-10-30: 13,984 prints worth $277.16B, $107.38B of it in dark pools.
- Most traded in dark pools and blocks: QQQ ($16.44B), SPY ($14.91B), NVDA ($9.47B), AAPL ($9.03B), MSFT ($6.76B).
Updated 2026-11-02 16:03 UTC