How much stock trading happens in dark pools?
By Faizan Ahmad. Updated .
Dark pools in the strict sense, alternative trading systems (ATSs), handle roughly a tenth of US stock trading: 10.7% of share volume in the first quarter of 2023, spread across 33 venues, according to the SEC. All trading away from exchanges, including wholesalers that fill retail orders and other broker-dealers, was about 44%, and the SEC's chair put it at about 45% for 2023. When you read that "nearly half of trading happens in dark pools," that is the off-exchange figure, not dark pools alone.
Where do US stocks actually trade?
The clearest recent breakdown comes from an SEC rule release published in March 2024, using first quarter 2023 data from Cboe and FINRA:
| Where | Number of venues | Share of all share volume | Share of off-exchange volume |
|---|---|---|---|
| Exchanges | 16 | 55.9% | n/a |
| Wholesalers | 6 | 26.9% | 60.9% |
| Dark pools (ATSs) | 33 | 10.7% | 24.2% |
| Other FINRA members | 222 | 6.6% | 15.0% |
On an average day that quarter, about 11.7 billion shares worth $522 billion traded in US-listed stocks. Exchanges handled about 56% of the shares and off-exchange venues about 44%. Wholesalers, which many retail brokers send their customers' market orders to, were the biggest off-exchange group by far: more than twice the dark pools' share. Single-dealer platforms, where a firm fills institutional orders from its own inventory, were about 4% of volume, according to the same release.
Why do the numbers you read disagree?
You'll find figures from 10% to over 50% for "dark pool" trading. Four things explain the gap:
- Dark pools vs all off-exchange. The SEC uses "dark pool" for ATSs that don't display quotes and says other off-exchange venues, such as wholesalers, are not dark pools. Headlines often lump them together. That turns 10.7% into 44%.
- Shares vs dollars. Off-exchange venues handled about 44% of shares but 41% of dollar volume in the first quarter of 2023.
- The period. The share moves. The SEC chair testified that on February 9, 2021, at the height of the meme-stock trading, more than 50% of shares traded off-exchange, and that from January 4 to February 26, 2022, the daily average was 47%.
- The stock. The split differs from one stock to the next, which is why FINRA publishes off-exchange volume security by security.
How has dark pool trading changed over time?
| Period | Dark pools (ATSs) | All off-exchange | Source |
|---|---|---|---|
| 2009 | 7.9% | 25% to about one-third (SEC sources differ) | SEC release (2018); SEC chair testimony (2022) and statement (2024) |
| Second quarter 2015 | 15.0% (38 ATSs) | n/a | SEC release (2018) |
| First quarter 2018 | 11.4% (33 ATSs) | n/a | SEC release (2018) |
| January 2021 | About 9% | About 47% (53% on exchanges) | SEC chair speech (2021) |
| January 4 to February 26, 2022 | n/a | 47% | SEC chair testimony (2022) |
| First quarter 2023 | 10.7% (33 ATSs) | About 44% | SEC release (2024) |
| 2023 | n/a | About 45% | SEC chair statement (2024) |
The pattern: dark pools have stayed in a band of roughly 8% to 15% of share volume, while all off-exchange trading grew from a quarter to a third of volume in 2009 to nearly half. Most of that growth came from trading outside dark pools; by 2023, wholesalers alone handled 26.9% of all share volume.
Is dark pool trading concentrated in a few pools?
No. In the first quarter of 2018, the busiest ATS executed about 20.1% of all ATS share volume and only 2.3% of total US stock share volume, according to the SEC. Dark pool trading is split across dozens of venues, each run by a broker-dealer. The SEC posts each one's Form ATS-N, which describes how it works.
Where can you check the current number?
FINRA publishes how much each ATS, and each off-exchange firm above a volume threshold, traded in every stock each week. Under FINRA Rule 6110, the data comes out two weeks after the week ends for Tier 1 stocks (those in the S&P 500, the Russell 1000 and selected exchange-traded products) and four weeks after for everything else. So the official per-venue numbers always lag. Trade-by-trade prints come from FINRA's trade reporting facilities instead, and that is what Tradytics' dark pool pages are built from. More in what are dark pool prints?
What this means when you look at dark pool data
On Tradytics, every trade reported to FINRA's facilities is labeled Dark pool. That label covers the whole off-exchange market, the roughly 44% bucket, not only the 10.7% that ATSs handle. A large print marked Dark pool could be an ATS match, a wholesaler's fill or a broker-dealer trading from its own inventory or crossing client orders. That is one more reason a single print can't tell you which way the money is leaning, and why traders compare each stock with its own usual day.
Big size doesn't only go dark, either. On October 30, 2026, QQQ's largest dark pool print was 1,250,000 shares at $690.23 at 12:51 PM ET, an $862.79M trade and about 15% of QQQ's usual day of large dark pool and block trades ($5.67B). Its two largest prints of the day were not dark pool trades at all: 3,000,000 shares at $690.58 at 4:00 PM ET and 2,700,000 shares at $691.425 at 4:03 PM ET, both on NYSE Chicago, an exchange.
How to see it on Tradytics
The Dark pool prints page opens with the session's totals: total value, dark pool dollars, block dollars, shares and number of prints, followed by each large print with its venue. Each stock's dark pool page, such as SPY's, shows how much traded today 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
Is more than half of stock trading done in dark pools?
No. Dark pools, meaning ATSs, handled 10.7% of share volume in the first quarter of 2023. All off-exchange trading was about 44%, and it has topped 50% on some days, such as February 9, 2021.
Does dark pool volume count in a stock's daily volume?
Yes. FINRA states that ATS trades in listed stocks are reported to a FINRA trade reporting facility and published on the consolidated tape along with exchange trades, so they are part of the volume you see.
Why does off-exchange trading jump when retail traders pile in?
Retail brokers often route their customers' market orders to wholesalers, which trade off-exchange. So the off-exchange share tends to rise with retail activity: on February 9, 2021, at the height of the meme-stock trading, it passed 50%.
Is dark pool volume the same as short volume?
No. They are different datasets that often get confused. See is off-exchange or short volume the same as dark pool volume?
Where does my own order go?
That depends on your broker's routing. Does my order go through a dark pool? shows how to check.
Sources
- SEC, Disclosure of Order Execution Information, Release 34-99679 (March 6, 2024): first quarter 2023 volume by venue type (Table 6), average daily volume, share vs dollar split, single-dealer platforms and retail routing to wholesalers.
- SEC, Regulation of NMS Stock Alternative Trading Systems, Release 34-83663 (July 18, 2018): ATS shares of volume in 2009, 2015 and 2018, the busiest ATS's share, and the definition of dark pools.
- SEC Chair Gary Gensler, Prepared Remarks at the Global Exchange and FinTech Conference (June 9, 2021): January 2021 split of 53% exchanges, about 9% ATSs and about 38% mostly wholesalers.
- SEC Chair Gary Gensler, Testimony Before the Senate Banking Committee (September 15, 2022): off-exchange at about one-third of volume in 2009, more than 50% on February 9, 2021, and a 47% average from January 4 to February 26, 2022.
- SEC Chair Gary Gensler, Statement on Minimum Price Increments, Access Fee Caps, Round Lots, and Odd-Lots (September 18, 2024): about 45% of share volume in dark markets in 2023, up from 25% in 2009.
- 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 16:05 UTC