The previous example demonstrates a step acquisition with control achieved with the most recent purchase. Post-control acquisitions by a parent of a subsidiary stock, however, often continue as well. Recall that the acquisition method measures an acquired firm at its fair value on the date control is obtained. A parent subsequent subsidiary stock acquisitions do not affect these initially recognized fair values. Once the valuation basis for the acquired firm has been established, as long as control is maintained, this valuation basis remains the same. Any further purchases ( or sales ) of the subsidiary's stock are treated as equity transactions.