By Tim McLaughlin

BOSTON (Reuters) - Nearly 20 years after Fidelity Investments first sank money into Exa Corp, the small software company has turned into a bright spot in the rough-and-tumble market for U.S. initial public offerings.

While shares of better known and bigger companies such as Facebook Inc, Zynga Inc and Groupon Inc trade far below their IPO price, Exa's stock is up 20 percent since its public debut in early July.

Exa, a microcap stock with a market value of $160 million, became a publicly traded company more than 20 years after its founding. And it didn't come to market with any fanfare. But it employs about 200 people and most of the top automakers, including Toyota Motor Corp, use Exa's design software to reduce development costs through simulated testing.

Exa has survived rough financial cycles and its own growing pains thanks mostly to a patient group of investors, U.S. regulatory filings show. Affiliates of Boston mutual fund giant Fidelity, for example, began investing in the company in the early 1990s, waiting decades before realizing stock sale gains in the public market.

Canaccord Genuity analyst Richard Davis said in a research note he expects Exa to extend into other industries such as aerospace. Exa shares are up about 16 percent in the past week. The stock was trading at $12.00 Friday afternoon on Nasdaq, above its $10 IPO price.

The company on Thursday said revenue in the quarter that ended July 31 rose 9 percent to $11.8 million from year-ago levels. Net income was $898,000, compared with $482,000 in the year-ago quarter.

Exa's IPO generated net proceeds of about $35 million for the Burlington, Massachusetts-based company. FMR LLC, the parent of Fidelity, and affiliates sold about 2.1 million shares for $9.30 each, generating gross proceeds of $19.3 million, Securities and Exchange Commission filings show. Investors in the company before the IPO paid a weighted average price of $3.89 for each share of stock, SEC filings show.

Exa Chief Executive Stephen Remondi co-founded the company in 1991. His father, John Remondi, is a director of FMR LLC and a trusted adviser to Fidelity Chairman and Chief Executive Edward C. Johnson III. Stephen Remondi was not available for comment.

But during a conference call on Thursday evening, the younger Remondi said he sees growing demand for the company's software, including among tire makers looking to boost their edge in aerodynamics.

(Reporting By Tim McLaughlin; Editing by Steve Orlofsky)