By Sue Chang

The second quarter wasn't kind to some of Wall Street's best and brightest, and the period's rough spots are likely to show up in a coming wave of securities filings.

Institutional investment managers have 45 days after the end of the prior calendar quarter to disclose their equity holdings. Some have already made these 13F filings; others often wait till the last minute, and these reports frequently show up after the regular trading session.

Judging by the tepid performance of the stock market in the second quarter, many of the high-profile stocks in their portfolios are likely to have suffered.

The Dow Jones Industrial Average fell 2.5% in the three months ended June 29, while the S&P 500 index slid 3.3% and the Nasdaq Composite lost 5.1% for the quarter. Many individual stocks did a lot worse.

Warren Buffett, one of the most respected investors in the world, reported on May 15 that he bought 10 million shares of General Motors Co. (GM) in the first quarter. The stock tanked 23% in the second quarter to $19.72.

Billionaire George Soros's Soros Fund Management LLC bought into J.P. Morgan Chase & Co. (JPM) and Goldman Sachs Group Inc. (GS) in the first quarter. J.P. Morgan Chase slumped 22%, and Goldman Sachs shed 23% in the April-June period.

Activist hedge fund manager Bill Ackman's Pershing Square Capital Management owned large positions in J.C. Penney (JCP) and Citigroup (C) at the end of March. J.C. Penney skidded 34% and Citi surrendered 25% in the following three months.

Paulson & Co., John Paulson's hedge-fund firm, reported stakes in Bank of America Corp. (BAC) and Caesars Entertainment Corp. (CZR) in May. Bank of America stumbled 15% and Caesars, which went public earlier this year, fell 23%. Paulson also holds a sizable stake in the SPDR Gold Trust (GLD), which slid 4.3%.

On the whole, hedge funds lost money in the second quarter on lingering European uncertainties, but still fared better than the S&P 500 and the Nasdaq Composite indexes. The HFRI Fund Weighted Composite Index, made up of 2,200 funds with at least $50 million under management, slid 2.7% in the second quarter, HFR said last month.

Among Greenlight Capital Inc.'s marquee holdings, Apple Inc. (AAPL) slipped 2.6% while Marvell Technology Group (MRVL) lost 28%. David Einhorn's hedge fund reported a loss of 3.2% in the second quarter due in part to the ongoing European crisis and bad calls on Dell Inc. (DELL) and Best Buy Co. (BBY), which it exited at a loss.

SAC Capital Advisors, managed by Steven Cohen, had increased its stake in several tech companies, a move which it may be regretting. Advanced Micro Devices Inc. (AMD) fell 29%, Cisco Systems Inc. (CSCO) declined 19% and Hewlett-Packard Co. (HPQ) shed 16% in the second quarter. Only Oracle Corp. (ORCL) eked out a gain of 1.9% in the period.

Write to Sue Chang at AskNewswires@dowjones.com

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