Yahoo! Inc. (YHOO) released its earnings filing on 01/26. The company reported a change in quarter-over-quarter sales of -4.12% and posted an EPS (trailing twelve months) of .42.

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By now the market has had time to settle in and look closely at the numbers. A stock’s performance in the few weeks following an announcement, compared to other stocks in its industry, the industry as a whole, and market as a whole, really tells you how investors and analysts felt about the announcement.

Compared to peers

One way to gauge performance is look at a stock compared to other stocks in its industry with similar market caps. YHOO peer Baidu, Inc. (BIDU) has seen a 21.75% stock price gain over about the last month, while another peer, Google Inc. (GOOG) saw a -1.58% gain (loss). So with a return of -1.70%, Yahoo! Inc. saw less price gain than BIDU and under-performed GOOG’s price performance over the last month.

Compared to the S&P 500 Index

Now, let’s see how Yahoo! Inc. stock performance compares to the rest of the market by looking at it compared to the Standard & Poor’s 500 Index (.INX). Since 01/26, the S&P 500 index has returned around .9%, and again, YHOO saw about a -1.70% gain (loss) during that time. Could be better.

Compared to the rest of the “Internet Information Providers” industry

Since the YHOO announcement (about 30 days ago), the stock has posted a -1.70% gain (loss). Over that same period, the stock’s industry, Internet Information Providers, saw a – .90% gain (loss). That means YHOO that has under-performed its industry as a whole 88.89% since the earnings announcement. Small differences aren’t significant, but when the spread is large it indicates the stock is either much more or much less favored than its group as a whole.