WASHINGTON — Even as the Securities and Exchange Commission has stepped up its investigations of Wall Street in the last decade, the agency has repeatedly allowed the biggest firms to avoid punishments specifically meant to apply to fraud cases.

By granting exemptions to laws and regulations that act as a deterrent to securities fraud, the S.E.C. has let financial giants like JPMorganChase, Goldman Sachs and Bank of America continue to have advantages reserved for the most dependable companies, making it easier for them to raise money from investors, for example, and to avoid liability from lawsuits if their financial forecasts turn out to be wrong.

An analysis by The New York Times of S.E.C. investigations over the last decade found nearly 350 instances where the agency has given big Wall Street institutions and other financial companies a pass on those or other sanctions. Those instances also include waivers permitting firms to underwrite certain stock and bond sales and manage mutual fund portfolios.

JPMorganChase, for example, has settled six fraud cases in the last 13 years, including one with a $228 million settlement last summer, but it has obtained at least 22 waivers, in part by arguing that it has “a strong record of compliance with securities laws.” Bank of America and Merrill Lynch, which merged in 2009, have settled 15 fraud cases and received at least 39 waivers.