Well the core of value investing is buying shares when they are...

Well the core of value investing is buying shares when they are undervalued. The reduction in SP is a short term event and has little to do with the business. The business and long term view remains the same. The flow of money out of the market is purely institutional investors protecting profits as their only objective is profitability over a quarter. Institutional investors will sell shares in companies they expect to be huge in the company years.

Warren Buffet has long said investors shouldn't be happy with the SP rising and instead should be happy about the SP falling so the can continue to accumulate shares in good businesses. One of my favorite quotes of his (which I've quoted many times on HC): "investors are the only people who run out of the store when things go on sale."