This year s juiciest financial reading might be Berkshire Hathaway s report of its 2008 investment results, due March 1. Shares of the Warren Buffett investment vehicle have lost 33% in a year, vs. a 39% drop for the S&P 500 index. But with Berkshire (BRK.A) underlying stock positions last reported Sept. 30, investors can t be sure how the portfolio weathered the market s fourth-quarter abuse.

According to late January analysis by Barron s, a portfolio of Berkshire s top 16 holdings (as of its last filing) beat the market nicely last year but has lagged it in 2009. Late-year changes would likely affect those numbers, and only some of Berkshire s recent moves are publicly known.

Since October Berkshire has bought 13 million shares of Burlington Northern Santa Fe (BNI), raising its stake in the nation's second-largest railroad to 22%. Shares during that stretch have fallen 25% -- slightly less than the broad market -- due to concerns about the weak economy. But Burlington's fourth-quarter earnings per share jumped 41% and topped Wall Street estimates. This despite data that showed last week U.S. rail shipments were down 15% compared with a year ago.

Other recent Berkshire moves don t quite make for stock endorsements, either because Berkshire has lent money to the company instead of buying a stake in it or because it has secured rich, private terms not available to ordinary investors. In October Berkshire agreed to buy $3 billion worth of preferred stock from General Electric (GE) . The shares come with a 10% dividend, and Berkshire is entitled to buy $3 billion worth of GE shares at $22.45 -- about double the stock s current price -- any time over the next five years. A similar $5 billion preferred deal with Goldman Sachs (GS) also came with a 10% dividend, and gives Berkshire the right to buy $5 billion worth of common stock at $115, about 39% above its present price, within five years.

On Tuesday Harley Davidson (HOG) announced that Berkshire will lend it $300 million, with the funds being used by Harley s customer financing unit. Shares jumped 16%. The five-year notes carry 15% interest. That s not the sort of rate that allows for profitable re-lending to bike buyers, but it might relieve investors fears over credit losses, which helped send Harley s fourth-quarter profit down 58% from a year earlier.

Buffett pal Bill Gates made his fortune in software, not stocks, but his charitable endowment lost just 20% last year in the market. Gates disclosed the loss in a January letter he said he wrote on the advice of Buffett, whose own yearly letter to shareholders is widely read and quoted. In 2006, Buffett pledged $30 billion in Berkshire stock to Gate s charitable efforts.

Gates has bought big stakes in garbage collection and car sales via Cascade Investment, his money-management firm. From Jan. 13 to Jan. 26 Cascade bought 3.9 million shares of Republic Services (RSG) for $448.6 million. Gates now owns a 25% stake in the Ft. Lauderdale, Fla., trash company, counting shares held by Cascade and by the Bill & Melinda Gates Foundation. Republic s sales are projected to fall less than 2% this year, and profits are seen rising 13%. Shares have lost 17% in a year, less than half the broad market s drop.

Another Ft. Lauderdale company, car dealer AutoNation (AN) has seen its stock drop from $22 to less than $10 in two years, including an October dip below $4. Gates has bought steadily since November, amassing a 12% stake. Fourth-quarter sales for AutoNation plunged 34% from a year ago, but the company turned a profit, reduced inventory and trimmed debt.