Are Baidu and Google Earnings Related?

After the close on Thursday, even as traders were marveling at the 13% move after Google announced its earnings triumph, Baidu was also up substantially after hours (2.8%) on no apparent news. This got me wondering whether there was any steady relationship between the two – after all, Baidu is colloquially “the Google of China,” so it isn't hard to imagine people trading the two stocks similarly.

On the day after Google reported earnings, the returns of the stocks have had the same sign for the last seven quarters, with a correlation over the last eight quarters of 0.72. I'm using after-hours prices for 7/14/11.

With respect to the relationship between earnings results, they have been slightly negatively correlated of late (-0.22), but that's just because Baidu never misses, while Google occasionally does. The tables below show earnings estimates, actual reports, and next day return data for the last eight quarters. I just grabbed what was ready to hand; maybe more historical data would show something more interesting.

For the sake of completeness, plotted below are the relationships between the size of the earnings beat/miss and next-day returns. GOOG has a nice, obvious linear relationship with R^2 of 0.82, while BIDU is kind of a mess. But that's what happens when n=8, isn't it?

Earnings and price data courtesy of Livevol.