Interesting stuff.
A shareholder may exchange QSB stock for stock in another corporation as part of a tax-free incorporation under Sec. 351 or a tax-free reorganization under Sec. 368. If the stock received in the transaction would not, on its own terms, meet the definition of QSB stock, the stock is nonetheless treated as QSB stock in the hands of the transferring shareholder because the stock that was exchanged was QSB stock.72 The holding period of the QSB stock received in the transaction begins on the date the exchanged stock was acquired; however, upon a subsequent disposition of the stock, only the appreciation inherent at the time of the original transfer may be taken into account under Sec. 1202.