Some of the brokerage firms that helped pique American’s interest in stocks are now luring them into something much riskier: stock options.

As the stock market soars to new heights, E*Trade, Ameritrade and Charles Schwab are advertising the potential rewards of options, which give buyers the right to buy or sell stocks at predetermined prices in the future. Options, like their cousins, futures, have traditionally been the domain of Wall Street traders. But the brokerage firms say futures and options can be profitable for ordinary investors, too — a claim that, while true, does not square with many investors’ actual experience.

“We’re looking for newcomers who want to get serious,” Schwab says on its Web site.

While relatively little research has been done on the success ordinary investors have in trading options, analysis done for The New York Times by SigFig, a company that tracks 200,000 retail investors, showed that people who traded options last year received only about one-fifth the returns of people who did not trade options: 1.1 percent compared to 5.1 percent.

The brokerage firms do not release data about customers’ trading, and they are generally hesitant to detail the expansion of this business. But it has clearly been an area of growth. An analysis of scattered data from company filings and presentations indicates that derivatives trading, which includes options, has risen at all the major firms since the financial crisis of 2008, which left many Americans with big losses in their investment portfolios.