Martin Rogers has been regularly trading options from his mobile phone since last summer, after dabbling in stocks and derivatives for years. A pharmaceutical representative based in Winter Garden, Fla., Mr. Rogers is often on the road and has been drawn to the ease of trading between meetings and the possibility of high returns.

“I could invest $100 and get 100% return on it,” Mr. Rogers said. When he first started trading options, he was blown away by the results. “Just looking at how powerful it was to make money … it was hard for me to sleep for a couple of days.”

Mr. Rogers is among the ranks of individual investors looking to magnify bets on stocks. U.S.-listed options volumes hit a record last year as market volatility roared back, a welcome boost to an industry that dealt with years of flatlining participation.

Brokerages, which typically generate higher profits from options trades than stocks, say individual activity is growing. The number of options trades at Charles Schwab Corp., one of the biggest online brokers, climbed 36% in 2018 from the prior year, with the number of households that had placed an options trades up 17%. At E*Trade Financial Corp. , derivatives trades, most of which are options, were in the first quarter the third highest on record. Since the start of 2016, the share of accounts there that are approved to trade options has risen to about a quarter from 15%. Fidelity Investments says the number of households trading options there has grown in recent years, posting an 11% increase in 2018 from the prior year.

Options are contracts that give the right to buy or sell stock at a specific price later in time. Used by hedge funds and pension funds, they can be used to protect portfolios, generate income or bet on popular companies that have grown expensive in the stock market. But the appeal for some everyday investors can be the prospect of winning big quickly. The catch: The prospect of great returns is paired with high risk. When buying call or put options, investors risk losing all of the options premium paid. Selling options can also be treacherous if done improperly, leaving investors on the hook to buy shares of companies at unattractive prices if the contracts are exercised.