TD Ameritrade Holding Corp.  said Tuesday that it had resolved technology issues that slowed trading and other functions on its Thinkorswim derivatives platform.

The retail brokerage cited a problem with one of Thinkorswim’s market-scanning functions, which affected customers Monday and resurfaced shortly after the open Tuesday.
“We’ve identified the issue and resolved it,” said Steve Quirk, senior vice president of trading for the company, saying that systems were functioning normally as of 10:45 a.m. CDT.

Investors reported long load times and stalled charts Tuesday, prompting an apologetic message from the brokerage.

Joshua Belanger, founder of options information website OptionSizzle.com, was among those reporting the difficulties.

“Pretty much I didn’t have any access to my funds or ongoing trades” for several hours Monday and Tuesday, he said.

Belanger said the trouble started Monday morning when he and his site’s subscribers could not log into their accounts. Once they do get on, access was slow and spotty, he said.

Quirk said the issue was tied to a scanning function that allows customers to design scripts for monitoring market moves.

The matter was unrelated to TD Ameritrade’s recent expansion of futures and foreign exchange trading to a broader range of TD Ameritrade users via the Thinkorswim platform, Quirk said.

TD Ameritrade has dealt with a range of technology issues in recent months, affecting stock quotes and access to its Web site.

Some of those problems were linked to a carrier in its network that connects to various Internet service providers throughout the country, the company said.