Dark Pool Prints Explained: What They Show

By The Oracle · For education, not financial advice.

A dark pool print is the public record of a stock trade that executed away from the exchanges, in a private venue that shows no order book before the trade. The trade is reported to a FINRA trade reporting facility within seconds and appears on the consolidated tape with its size, price and time. What a print does not show is who bought, who sold, which side started the trade, or why. That is why prints are context for where large size changed hands, not a reason to trade on their own.

What a dark pool is

A dark pool is a private trading venue, most often an alternative trading system (ATS) run by a broker-dealer. Large investors use them to buy or sell big blocks without showing the order to the market first. If a fund displayed a 2-million-share sell order on a public exchange, other traders could step in front of it and push the price down before it filled. In a dark pool the order is matched quietly, usually at or near the midpoint of the public bid and ask.

“Dark” refers to the missing quote before the trade, not to anything illegal. Dark pools are registered with the SEC and supervised by FINRA. They are also only part of off-exchange trading: much of the rest is retail orders filled directly by wholesale market makers. On the tape, both show up the same way, as trades reported through FINRA rather than on an exchange. Together, off-exchange trades have made up roughly 40% to over half of US stock volume in recent years.

What a print shows

• Ticker, size and price. How many shares traded, and at what price. Size × price gives the dollar value, the quickest measure of significance.
• Time. When the trade executed, and when it was reported. The two can differ.
• Venue code. Off-exchange trades carry FINRA’s code, not an exchange’s. The specific dark pool is not named in real time; FINRA publishes volume by venue weekly, weeks later.
• Condition flags. Codes that say whether the trade was reported late, happened outside regular hours, or was booked at an averaged or earlier reference price.

What a print cannot tell you

• Direction. Every print has a buyer and a seller. A print at the midpoint gives no hint which side was keener, and a print at the bid or ask gives a weak hint at best.
• Intent. A block can be a fund building a position or trimming one, an index fund rebalancing, or a dealer hedging a derivatives trade.
• The whole order. One print may be a single slice of a much larger order worked over days.
• What comes next. The trade has already happened. Nothing in the print says where price goes from here.

Prints to set aside

Some prints carry a price that is not where the shares changed hands at that moment. Treat them as levels and you end up drawing lines at prices nobody actually paid.

• Average-price trades. A broker fills a client through the day, then reports the whole fill at the average price.
• Prior reference price trades. A trade booked at a price from earlier, such as an agreed price from the morning or the previous close.
• Late and out-of-hours reports. A print reported after the close, or long after it executed, can sit at a price the market has already left behind.

From prints to levels

One print is an anecdote. Repeated size at one price is more useful. The usual approach is to add up the dollar value of real-price prints at each price over the last week or two, then mark the prices where the most money changed hands. Two habits help.

• Compare with the ticker’s usual. A $300 million day is routine in SPY and enormous in a mid-sized company. Judge dark dollars, and the dark share of volume, against the name’s own recent history.
• Treat levels as context. A heavy dark pool price shows where large size traded. It does not mean the same buyers will be there to defend it.

A worked example

The 10:42 print is large, but it sat almost exactly at the midpoint, so it says nothing about who was keener. The $198 to $199 band is the level worth noting, because repeated size traded there over two weeks. It is a place to watch how price behaves, not a floor.

The after-hours print at $197.40 looks dramatic, a big block below the last price, but it is an average-price report. Its price is the average of fills spread over the day, not a trade at $197.40, so it does not belong on the chart as a level.

Dark pool prints and options flow

The two answer different questions. Options flow shows trades in contracts with a strike and an expiry, where the fill against the quote gives a rough bullish or bearish read. Dark pool prints show stock changing hands, usually with no read on direction at all. When both point at the same ticker on the same day, such as heavy call buying and a cluster of large stock prints, that is a reason to look closer. It is still not proof of anything.

Dark pool data in MomoEdge

MomoEdge records dark pool prints for the major index and sector ETFs and a handful of the largest stocks. The terminal’s DARK POOL widget compares today’s dark money and largest print with the ticker’s usual, and the CHART tab can draw the last ten sessions’ dark pool levels as dashed lines, built from real-price prints only. You can see those lines on sample data in the terminal tour, on its dealer levels and dark pool view, and the Terminal Field Guide explains how the terminal’s screens fit together. The $10K account shows every trade our team takes with real money, winners and losers, before commissions and fees. To read dark pool levels next to options flow and GEX on live data, you can see what the terminal includes.

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