Extended hours trading volume has traditionally been largely concentrated in the minutes and hours following the end of continuous trading at 4:00pm EST, in large part due to post-earnings trading activity. In Q1 2019 post-market trading (4-8pm EST) accounted for over 83% of all off-hours trading. Fast forward five years, so far in Q1 2025 pre-market trading (4-9:30am EST) has taken the lead and now accounts for over 55% of the shares traded during extended hours. The pre-market session has grown 15x since 2019 compared to 2.3x for the post-market session and just over 2x for the rest of the trading volume. This unprecedented growth in pre-market and off-hours trading is sizeable and persistent in notional terms as well. Despite still attracting most of the extended hours dollar value, the post-market session has dropped from 90% in 2019 to 73% today as daily notional has increased by a mere 2.1x compared to the pre-market’s 7x jump.

What’s behind the trend?

Not only has the pre-market session grown at a significantly faster pace than the post-market session, but this growth has largely been concentrated in the early hours of trading. Pre-7am trading accounted for less than 5% of the pre-market trading in 2019 but has increased more than fivefold over the last five years and now accounts for over 28%, as round-the-clock demand for US securities has grown both domestically and internationally. In contrast, the last thirty minutes of pre-market trading have lost their prominence dropping from 37% in 2019 to just over 16% to start 2025. Although one may be quick to attribute this to off-exchange trade reporting inconsistencies, the exact same trend is evident in pre-market trading on NYSE Arca. Whether off- or on-exchange, extended hours trading is shifting towards earlier times as retail and institutional investors across the globe ramp up their participation in US equities trading.

As the off-hours volume composition and investor mix has changed over time, so has the symbol composition. Historically, trading in the pre-market session has been skewed towards lower-priced symbols compared to the core trading session and post-market session, as retail flow commonly represents an outsized share of traded volume during this early window. This trend remains intact; 2025 pre-market volume has so far traded at a VWAP of $18, compared to $46 for the core session and $59 for the post-market session. When evaluating how each session’s VWAP has changed over the years, however, a clear trend emerges. Core and post-market VWAPs have tracked each other very closely in terms of YoY change, hovering around 0%. In contrast, the pre-market YoY change has completely decoupled from this trend, falling by more than 50% in 2025 compared to five years ago. Stated otherwise, trading in lower-priced securities not only accounts for a larger share of the pre-market session than the core or post-market session, but it has also shifted to even lower prices as the volume has increased.

The key driver behind this trend has undeniably been increased retail participation during the pre-market session. As pre-market trading volume on NYSE Arca has skyrocketed over the last five years, so has the retail participation - particularly on the liquidity-providing side of trades.

The effect of participant mix on trading volume and prices is also reflected in the fact that the VWAP of each of the two extended hours sessions is higher at the start and end of the core trading session and decreases rapidly as trading moves away from it and retail participation increases.

Volume shifts on-exchange as the search for liquidity intensifies

On-exchange trading has been a big beneficiary of this changing landscape. NYSE Arca has long established itself as the leader in off-hours market share and has rivaled off-exchange trading in pre-open market share in recent years. As of 2024 NYSE Arca has overtaken the TRF as the number one destination for pre-market liquidity with over 32% of all shares traded. This lead has widened even further in January 2025 to more than +2%.

The 8am effect

So far in this post we have been examining market dynamics using actual trade times, yet in the current trade reporting landscape, the time a trade happens and the time a trade is reported to the consolidated tape (and hence made available to the rest of market participants) can vary greatly for off-exchange trades.