Nasdaq OMX is negotiating with trading firms over payouts for losses incurred by a glitch with one of the bourse's algorithms earlier this week, according to the Wall Street Journal.
Nasdaq had to suspend trading in more than 80 securities on Monday after software malfunction saw "invalid and stale market data" fed to firms.
The problem involved Nasdaq's recently introduced quoting system for market makers which automatically enters quotes for them if they have not themselves by 9:28 am.
According to the WSJ, citing people familiar with the issue, the glitch may have been caused by the program's failure to correctly account for the three-day weekend.
Exchanges quickly agreed on Monday to cancel all trades that were 30% above or below a benchmark price.
However, according to the WSJ, negotiations are ongoing with some Nasdaq market makers, who took on significant losses when trades triggered by the duff data were not cancelled. Firms are understood to want repaying for losses, angered at the delay in letting them know which trades would be broken and which would stand.
Nasdaq in Talks Over Losses From Monday Glitch - WSJ