After-Hours Trading Trends; New Non-Penny Options Market Share Record

After-Hours Trading Trends; New Non-Penny Options Market Share Record

Equities Exchange Highlights

Consolidated average daily equity volume dipped to 17.8 billion shares in April following two consecutive months at around 20 billion shares. Retail activity has been steady on MEMX in recent months, with 183 million average daily add volume in April. Retail accounted for 45% of MEMX add volume during the month.

We continue to monitor after-hours activity ahead of industry plans to expand exchange trading into overnight hours (8pm-4am) in December. Figure 2 shows the growth in overnight average daily volume to 159 million shares in April, up 305% year-over-year. Blue Ocean ATS, which is powered by MEMX, is the leading overnight U.S. equities trading platform and has, at times, restricted trading in certain symbols to remain below the 5% ADV threshold under Regulation ATS. Blue Ocean is pursuing Fair Access compliance to eliminate the need for such restrictions.

Figure 3 shows the distribution of trading volume across 30-minute intervals in four sessions: Overnight (8:00pm-4am), pre-market (4am-9:30am), regular trading hours (9:30am-4pm), and post-market (4pm-8am).

While overnight trading has grown rapidly, it remains the lowest volume segment, accounting for less than 1% of total daily volume. Overnight activity is driven primarily by retail participation from the U.S. and Asia. Sunday evening sessions are often more active, reflecting pent-up demand and event-driven positioning. Overnight ATS market data is valuable and can help identify directional bias and emerging demand driven by global or after-hours events. Institutional participation remains limited given the lower liquidity and wider spreads.

The pre-market (4am-9:30am) serves as an important period for price discovery ahead of the opening auction. It accounts for roughly 6% of total daily volume, with liquidity gradually building into the open. “Early bird” trading from 4am to 7am is influenced by European market activity. Participation includes both retail and institutional investors with early positioning and reaction to global information flows. In April, MEMX market share in the pre-market session was 5.1%.

Regular trading hours (9:30am-4pm) account for roughly 83% of total volume and remain the liquidity anchor, particularly for institutional participants. Volume is heavily concentrated in the first 30 minutes (9:30-10am) and last 30 minutes (3:30-4pm), which include the opening and closing auctions and are the most active time periods of the trading day.

The post-market session (4pm-8am) accounts for roughly 10% of total volume, with much of the activity concentrated in the first 30 minutes (4-4:30pm). Trading reflects a mix of off-exchange internalization and executions near closing auction prices, alongside portfolio rebalancing and reactions to earnings and late-day news. The segment is relatively mature and stable, with participation from both institutional and retail investors and relatively higher liquidity during the first hour or so.

Options Exchange Highlights

MEMX Options average daily equity volume increased 36% year-over-year to 2.7 million in April. Total market share was 3.9% and regular-electronic market share was 7.3%.

MEMX non-penny options market share hit another market share record of 18.3% of regular-electronic volume in April. Penny market share was 7.0%.

The figure below shows the distribution of options contract volume across 30-minute intervals from 9:30am to 4:15pm in April. Volume was heavily concentrated in the first couple hours (9:30am-11:30am), which accounted for 45.3% of total contracts traded. The first 30 minutes (9:30-10am) accounted for 17% of volume. MEMX market share was consistent across all time periods. Exchanges offer trading in a limited set of securities from 4:00pm to 4:15pm, generally just indexes and ETPs. Cboe has global trading hours in certain index options, including SPX, VIX, and XSP. Similar to equities markets, exchanges are discussing extended options trading hours, possibly starting with sessions from 7:30pm to 9:30am and 4pm to 4:15pm (additional symbols) as an initial first step.