When trading ex dividend (which is 0,6 $) the stock is worth 0,6 $ less, because the buyer will not get paid this dividend. Adjustment in the way is used it means that calculating the change in the stock price yahoo factors in the value reduction of the ex dividend status. That is way at the close of today yahoo shows at a closing price of 12 3/8 a stock price change of just -1/8 although the stock closed at 13 1/8 on the day before. Sorry that I caused confusion. Klaus
Another interesting wrinkle on the ex-dividend adjustment comes into play if you sell covered calls on your position, especially if you had September $12 1/2s in play.
The adjustment means that these calls are no longer in the money and may well not be called away Friday at expiration. Which is certainly preferable to the PZN shareholder, since you can sell at that price anyway if you wish, or you can just sell new calls for even more income in addition to the dividend yield.
Of course, the astute BUYER of these calls would have exercised his option the day BEFORE PZN went ex-dividend, and recieved the dividend. Of some sixty contracts I have outstanding, exactly ONE was exercised.
Some time ago I raised this issue as to the special. I write calls against PZN and I do not know how thy will handle the price break that distribution of the special will cause. The exchanges have the option to re-strike the options if the distribution is serious enough (counts like a business reorganization).