If the stock market is rigged to fleece the little guy, someone forgot to warn the little guy.

Trading in online brokerage accounts that cater to individual investors is at an all-time high and they attracted new assets every quarter since 2010, according to analyst Ana Avramovic at Credit Suisse Group AG. Overall, U.S. equity trading volume is on pace to snap a four-year slump.

“Despite talk of flagging investor confidence and increased scrutiny of market participants, data from retail brokers show that the retail crowd is more engaged than ever,” Avramovic wrote in a report last week.

Combined daily average revenue trades at E*Trade Financial Corp., Charles Schwab Corp. and TD Ameritrade Holding Corp. rose 24 percent in the first quarter from the previous year and reached the highest level ever, according to Raymond James Financial Inc. analyst Patrick O’Shaughnessy, who this week raised his rating on E*Trade to the equivalent of buy. The stock fell 21 percent between March 20 and May 15.

A few other data points he highlighted: E*Trade customers purchased a net $3.9 billion of securities in the first quarter, matching the strongest buying since the company began reporting the metric five years ago, and the brokerage attracted a record amount of new assets.

‘Flash Boys’

The company also reported that daily trades grew 21 percent from the previous year in April, the month author Michael Lewis dominated financial headlines with claims of a rigged stock market in “Flash Boys.” (A claim that provoked a response from SEC Chairman Mary Jo White. See the Financial Advisor story "No Changes In SEC's High-Frequency Trading Stance.")

Overall U.S. trading is up 8.5 percent this year to an average 6.7 billion shares a day. Part of the pickup can be attributed to a change in volume measurements. Odd-lot trades, orders to buy or sell fewer than 100 shares, were included in the data starting in December. They accounted for about 3 percent of volume until the beginning of April, when odd lots picked up, according to Avramovic.

All of this could conjure up the old Wall Street trope that retail investors are always late to the bull-market party and their exuberance is a sign that the keg is almost kicked. Not to mention that U.S. equity mutual funds are winning net inflows for a second year after six years of withdrawals.

Noisy, Unreliable