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: A day after shares of streaming provider Netflix (NASDAQ:NFLX) soared 11% on a rating upgrade, those gains were entirely washed away on (drumroll, please) a rating downgrade as the stock fell 11%.

So what: Countering Morgan Stanley's argument that content-cost fears were overblown and the company didn't face a strong threat from Amazon.com, Bank of America today downgraded shares from a buy all the way to "underperform" because the stock had passed its price target of $72. Analyst Nat Schindler said, "Throughout the quarter, our concerns have grown surrounding the health of the domestic streaming business and the timing of the international streaming profitability," adding, "we now believe the risks outweigh the reward heading into Q3."

Now what: Of course, Netflix's share price is now under $72, so maybe Schindler will decide to upgrade it to hold now. Who knows? If you're getting dizzy following these yo-yo movements, you're not the only one. In my opinion, the market gives too much weight to these analyst ratings. After all, there are 30 analysts covering Netflix, so why should one's upgrade or downgrade sway the stock so much? Presumably, the other 29 still have the same opinion they had before.

As I said yesterday, I'm concerned about Netflix's high valuation and lack of consistent profitability at the moment. I'd wait for it to prove the value of its international expansion before getting invested.

Fool contributor Jeremy Bowman holds no positions in the companies in this article. The Motley Fool owns shares of Netflix, Bank of America, and Amazon.com. Motley Fool newsletter services have recommended buying shares of Amazon.com and Netflix, as well as creating a bear put ladder position in Netflix. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. Try any of our Foolish newsletter services free for 30 days. The Motley Fool has a disclosure policy.