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 MannKind (NASDAQ:MNKD), a biopharmaceutical company focused on developing therapeutic products to treat diabetes and cancer, were absolutely whipsawed following the release of the Food and Drug Administration's decision to approve its inhaled insulin therapy, Afrezza, for patients with type 1 and type 2 diabetes. Shares surged nearly 5% immediately following the late-day approval, then collapsed as much as 26% from its high of the day to ultimately finish lower by 5.5%. Shares have since regained a little ground in after-hours trading.

So what: Under normal circumstances a drug approval by the FDA would lead to a move higher in a company's shares, however this approval came with a couple of warnings that didn't appear to sit well with investors. Specifically, the FDA approved Afrezza with a boxed warning label indicating that it shouldn't be used in patients that have chronic lung diseases like asthma or chronic obstructive pulmonary disease, or COPD, because of reports during its study of breathing spasms in chronic lung disease patients. The agency also advised against smokers using the drug.

Now what: This is understandably a push-pull in terms of positive and negative news. On one hand there had been concern that MannKind wouldn't get the nod in type 1 diabetes, but after eight years of studies and a prior complete response letter from the FDA it now has access to some 25.8 million diabetic patients. Afrezza is fast-acting and incredibly convenient relative to administering an insulin injection, so it could be a notable advance in patient quality of care.

However, for as many potential patients as Afrezza has access to, it also will lose quite a few patients from its patient pool because they're smokers, have asthma, or have COPD. The real hang-up seems to be in determining how much of a market Afrezza has left following this warning label. In addition, we're still waiting on where MannKind will price Afrezza, whether or not it'll find a partner to help launch its drug, and how it'll finance this venture with its cash on hand quickly dwindling.

All told, it's a genuinely positive day for most diabetics in the U.S. who will soon have a new treatment option available. For MannKind, though, that optimism is considerably more guarded until it provides investors with answers to some of these key questions above.