Assuming you are talking about in relation to Magna, I am not...

Assuming you are talking about in relation to Magna, I am not surprised at all. Once Magna have 20% of the stock they reach the takeover threshold and have further restrictions in relation to acquiring more shares.

As such if you assume that they are awaiting good flow results before potentially making a takeover bid the sensible thing to do would be:
- to acquire enough stock to get you close to the 20% threshold without going over at least a few weeks before the news
- allow the reduced turnover after you have acquired the above stock to hopefully bring the price back down a bit
- upon announcement of the awaited news continue to acquire up to the threshold before announcing your intention to make a takeover bid.

After the last announcement they are only required to make a further announcement once their interest change by a further 1% of the company. The other few steps seem to have occurred though. Whilst the price hasn't come back much the volume has fallen away quite a lot in the last few days and this would indicate to me that Magna have probably acquired all they plan to until further announcements are made.