Charles Schwab
Charles Schwab's data is closely watched as an indicator of retail investor sentiment. Reuters

Charles Schwab Corporation (NASDAQ:SCHW) said on Friday that its clients made 505,400 trades during the average day in May, a 17 percent increase from year-ago levels, and 8 percent higher than April’s level.

Schwab’s data is closely watched as an indicator of retail investor sentiment.

Schwab said total new assets brought to the firm in May were negative $1.9 billion. However, that number included $10.3 billion in outflows related to a mutual fund clearing services client. “The clearing outflow is part of a planned transfer totaling approximately $80 billion occurring over an extended period. Transfers to date related to this client total approximately $18 billion,” Schwab said.

Total client assets rose 20 percent from a year ago to a record $2.11 trillion as market appreciation contributed to gains.