A killer virus on the prowl around the planet evidently was not on investors’ tiny, fevered brains Tuesday as they reminded us yet again that betting heavily on a rally when stocks have been down for two straight days is nearly always a winner. The S&Ps rose an impressive 32 points, with a corresponding gain in the Dow Industrials to 28,722 that has  made 30,000 an odds-on bet. The leap that Apple shares took when record earnings were announced after the close is likely to have a bullish impact on the shares of Microsoft , Facebook, Amazon and Boeing when the respective companies announce earnings between now and Friday.