Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of organic-foods maker Annie's (UNKNOWN:BNNY.DL) are up roughly 38% Tuesday in the wake of an $820 million buyout from General Mills (NYSE:GIS).

So what: Annie's shareholders will get $46 per share in cash -- an amount roughly $0.30 below the stock's price at this writing -- and the company's brands will join General Mills' existing lineup of natural and organic products. Annie's has roughly 150 products available in more than 35,000 retail locations in North America, but according to recent financial data, General Mills' organic-food division pulled in roughly $330 million in its last fiscal year, ahead of Annie's $204 million in overall net sales.

Now what: The buyout offer grants Annie's a P/E multiple of roughly 67, which is approximately twice its EBITDA multiple and about four times its trailing 12-month sales. General Mills will fund the buyout with its existing credit line, but with nearly $1.9 billion in trailing 12-month free cash flow, the food giant can pay down any acquisition costs rather quickly. This is one of a number of smallish natural-foods buyouts over the past year, and since this deal is very likely to close, Annie's investors should enjoy their windfall and go hunting for one of a shrinking number of independent natural-foods companies still worth investment.