The 100 wealthiest people on the planet shed $21.3 billion from their collective net worth as the Standard & Poor’s 500 Index posted its first weekly decline so far this year.

Activist investor Carl Icahn, the world’s 34th-richest person, was one of the week’s biggest losers, dropping $1.3 billion as shares of Icahn Enterprises LP sank 15.6 percent. He’s worth $20.4 billion, according to the Bloomberg Billionaires Index.

“The market was looking for an excuse to take a few chips off the table,” said James McDonald, chief investment strategist at Northern Trust Corp. in Chicago, which manages $759 billion. “The excuse was the minutes from the Fed, but investors realize the Fed’s picture really hasn’t changed that significantly. Today, there was good German confidence data.”

The S&P rose 0.88 percent yesterday, trimming a decline triggered by concerns that the Federal Reserve will scale back stimulus. The index rebounded from two days of losses after German business confidence rose more than forecast, adding to signs that Europe’s largest economy is gathering strength.

Carlos Slim, the world’s richest man, saw his net worth fall by almost $700 million as America Movil SAB, Latin America’s biggest mobile-phone company by market value, fell 2.2 percent, capping its third straight weekly drop. Slim, 73, has a net worth of $73.4 billion.

Microsoft Corp. co-founder Bill Gates, 57, is the world’s second-richest person with a $66 billion fortune, down $260 million for the week. Amancio Ortega, the 76-year-old founder of Inditex SA, the world’s biggest clothing retailer and owner of the Zara clothing chain, is No. 3 with a net worth of $56.1 billion. He lost $1.3 billion.

Suspicious Trades

Trailing Ortega is Warren Buffett, 82, who’s valued at $54.2 billion. A federal judge froze a Swiss account that the U.S. Securities and Exchange Commission says was used to carry out suspicious trades in H.J. Heinz Co. shares shortly before Buffett’s Berkshire Hathaway Inc. and Jorge Paulo Lemann’s 3G Capital Inc. announced they’d agreed to buy the company. The SEC on Feb. 15 sued the “unknown” traders over suspicious purchases of Heinz options through the account.

Lemann, 73, is Brazil’s richest individual. He has a net worth of $19.9 billion, down $20 million for the week.

Tax Loophole