optionsXpress (NASDAQ:OXPS), an online brokerage firm, had a record second quarter, despite a plunge in the equities markets in May and June. Revenues surged 66% to $47.3 million, with much of the growth coming from new accounts and increased customer activity.

optionsXpress is also highly profitable. In the second quarter, net income was up 69% to $18 million, or $0.29 per diluted share. The hefty profit increase is hardly surprising, given the company's industry-leading 62% pre-tax margins.

As the name implies, optionsXpress focuses on stock options, a market which has grown 22.5% per year over the past 10 years. Its customers are primarily retail, much like those pursued by Charles Schwab (NASDAQ:SCHW), E*Trade (NYSE:ET), and TD Ameritrade (NASDAQ:AMTD).

Over the past few years, optionsXpress has developed a highly cost-efficient brokerage platform, driving transactions by providing customers with educational and analytical tools. Kiplinger's magazine recently named optionsXpress the "Best Online Broker" in regard to the platform's overall appeal and value to the customer.

optionsXpress is also in the process of becoming self-clearing -- processing its own trades. This should help increase cost savings and provide a better customer experience. The move should be completed by the end of the year.

What's more, optionsXpress is impressively agile with cost-effective customer acquisitions. Total advertising expense per new account was $107 in the latest quarter, the lowest in the retail brokerage industry. In the second quarter, optionsXpress garnered 15,600 new accounts, for a total of 194,300.

optionsXpress has also been leveraging its platform into other areas, including the futures markets and its brokersXpress service, which allows financial advisors to manage transactions for their clients.

Before the fall-off in the markets, optionsXpress was trading at $32 to $33 per share. Despite the volatility, the company continued to grow at an impressive rate, but the stock price is now at about $25.50. That places the price-to-earnings ratio at a more palatable 28 times earnings, trailing the company's growth rate. Over the past six months, the company's net income has grown 76%.

Keep in mind that retail traders, for the most part, tend to stay on the sidelines in extremely volatile markets, as was the case with optionsXpress customers in the past few months. However, when markets stabilize, retail investors return, fulfilling pent-up trading demand. With markets improving lately, optionsXpress might get a growth spurt in the next few months -- which should be a nice driver for the stock.

Weigh your options with further Foolishness:

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Fool contributor Tom Taulli does not own shares mentioned in this article.