Tuesday was another good day for stocks. And no one had a better day than Google (NASDAQ: GOOG). Shares of the search-engine giant vaulted above $800 for the first time ever, riding a 1.76% gain to start this Presidents Day-shortened week. The stock is now up 21% in the last three months. As I wrote a couple weeks ago , it’s remarkable how much Google and its rival, Apple (NASDAQ: AAPL), have diverged in the five months since shares of the two largest tech stocks in the world simultaneously traded above $700 in late September. Apple shares have retreated 34%, falling all the way to $439 at one point. Google shares, meanwhile, have tacked on another 10%. It’s telling that Apple was flat today while Google advanced to a new all-time high and several other big-name tech stocks followed suit. Microsoft (NASDAQ: MSFT) gained 1% today. Facebook (NASDAQ: FB) was up 2.2%. The S&P 500 advanced three quarters of a percent to establish a new five-year high of 1,530.94. The Dow also hit a five-year high. It will be interesting to see where Google and the rest of the market go from here now that they’ve reached such rarefied air. Logic would suggest that stocks are grossly overbought. But that was the case entering 2013, and so far it’s done little to slow this unstoppable freight train of a rally.