purchase before sale where wash sale causes a loss. here's are examples.
buy 100 shares of X on 2/5, buy 100 shares of X on 3/1. on 3/2. you tell your broker to sell the lot purchase on 3/1 which results in a loss. the lot purchased on 2/5 is within the 30 day window of the 3/1 sale. result the 3/1 sale is a wash sale and the disallowed loss gets add to the tax cost basis of the 2/5 shares.
buy 100 x on 5/5. buy 100 of y on 5/6. sell the 100 y on 5/8 at a loss. x and y are substantially identical securities (don't ask how this is determined there is just too many possibilities). result you have a wash sale.
you can also have a wash sale if you sell securities at a loss in a taxable account and within that 30 day window purchase substantially identical securities in your or your spouse's retirement account. the reverse is not true - loss on sale in retirement a/c while purchase in a taxable a/c has no tax effect on either account.
the worse part in this situation the loss does not get added to the basis of the stock in the retirement a/c. such an action would be meaningless.
