Bernard "Bernie" Cornfeld (1930–1995) was a failed US mutual funds financier.

Bernald Cornfeld was born in Turkey in 1930. When he moved to the U.S., he first worked as a social worker but became a mutual fund salesman in the 1950's.

In the 1960s Cornfeld formed his own mutual fund selling company Investors Overseas Services (IOS) which he incorporated outside USA with funds in Canada and headquarters in Geneva, Switzerland. He hired 25,000 salesmen who sold his 18 mutual funds door-to-door all over Europe, especially in Germany, to small-time investors. He targeted US expatriates and servicemen who sought to avoid US income tax. Cornfeld called it "people's capitalism."

In the next ten years, IOS raised equal to $2.5 billion. Cornfeld himself invested into conspicuous consumption with lavish parties.

In 1968 IOS launched its "Fund of Funds," which meant investment in shares of other IOS offerings. The offering was very popular in the bull market times but then the market dropped and the guaranteed dividends had to be paid straight out of the capital—in effect, it had become a pyramid scheme. IOS was forced into Initial Public Offering to meet its costs. The next bear market made many investors cash their funds and the IOS stock value decreased further. Cornfeld later blamed a "bear raid" and that a number of German banks sold the stock short.

Share value decreased from $18 to $12 in the spring of 1970. Cornfeld formed an investment pool with some other investors but they lost when the share value dropped to $2. Even IOS employees and portfolio managers sold their shares.

Financier Robert Vesco who, at the time, was also in financial trouble, turned to Cornfeld and offered his help. Vesco proceeded to use $500 million worth of IOS money to cover his own investments in his International Controls Corp. When he was discovered, Vesco fled to Bahamas.

IOS collapsed and in the process ruined a number of US and European banks.

Cornfeld moved to Beverly Hills and tried to become a movie director. When he visited Geneva, Swiss authorities arrested him and he served 11 months in a Swiss jail before he could post bail and charges were dropped. He returned to Beverly Hills and to his previous lifestyle. At one stage he dated Heidi Fleiss.

Bernard Cornfeld died 1995 in England. He kept blaming Vesco to the very end.