The markets had another positive day, and amazingly, it was an announcement by the government that made it so. The Federal Reserve said it would buy up to $300 billion in long-term treasuries, and stocks applauded.

Here are today’s winners and losers:

Winners

Sun Microsystems Inc. (JAVA)
News of a possible acquisition by IBM sent the shares skyrocketing 78.9% on Wednesday. The tech giant’s stock closed at $8.89, a gain of $3.92 on the day.

American International Group Inc. (AIG)
Despite Liddy’s grilling on Capitol Hill, the insurer continues to ascend from its all-time lows. Shares closed at $1.38, up 42 cents, or 43.75%.

E*TRADE Financial Corp. (ETFC)
The company released a report that showed a slowdown in loan delinquencies, and shares responded by jumping 40.7%, or 37 cents, to end the day at $1.28.

AFLAC Inc. (AFL)
The insurer followed sector trends, surging 30.3%, or $4.89, to close at $21.04 a share.

XL Capital Ltd. (XL)
A ratings affirmation on XL Capital on Tuesday kept shares soaring on Wednesday. The stock closed the session at $5.12, a gain of 24.3%, or $1.

Losers

General Mills Inc. (GIS)
The company’s fiscal outlook failed to impress, and shares took a hit. The cereal king’s stock fell 11.2%, or $6.03, to $47.63.

Kraft Foods Inc. (KFT)
Kraft fell 4.4% on Wednesday, closing near its yearly lows. The stock finished at $22.29, a loss of $1.02 a share.

Yahoo! Inc. (YHOO)
It was a strange day for Yahoo. MySpace tested an application on the search company’s new home page and the technology sector saw strong gains – but Yahoo shares fell 4.1%. The stock closed at $13.40, a loss of 57 cents on the day.

Jacobs Engineering Group Inc. (JEC)
JEC dropped sharply at the open and made a valiant effort to rebound before falling 3.7% at the close. Shares ended the day at $40.32, down $1.55 on the day.

Intuitive Surgical Inc. (ISRG)
The surgical tools manufacturer fell 3.1% on above-average trading volume. Shares closed at $101.81, a loss of $3.30 on the day.