Perhaps Michael Saylor won't come out on top, at least not this week. Yesterday, Thursday, April 16, closed with a sharp slowdown in Strategy's purchases, while BlackRock's iShares concluded the day by acquiring another ~3,900 Bitcoin, renewing the challenge for which company will hold the highest number of $BTC in its treasury. It is a fight to the last purchase, which is contributing to the demand for Bitcoin and supporting its price.
On one side, Strategy is slowing down, at least regarding purchases through $STRC. On the other, iShares was the only one (along with Morgan Stanley) to record positive capital inflows yesterday.
BlackRock Responds to Michael Saylor
The coincidence of events is quite particular. Strategy's incredible capital machine, the preferred stock $STRC, naturally slowed down after the time threshold for dividends was triggered. Those who held shares as of April 15 are entitled to the dividend, making the shares much less attractive immediately after the lock-in.

This has led – as is visible from the price – to a sell-off of these securities, which prevents Strategy from issuing new ones. Unless the group decided to sell $MSTR common shares, there shouldn't have been any significant purchases yesterday.
A Different Situation at BlackRock
The situation remains very different among ETFs. Almost all of them lost capital, except for two: Morgan Stanley's (which, however, moves with much lower numbers than the top three) and BlackRock's iShares.

Data indicates inflows into BlackRock's ETF exceeding 291 million dollars, representing purchases of approximately 3,900 $BTC at yesterday's prices. This is likely enough to keep Strategy at bay in what has become a final rush for the takeover, which could be confirmed as early as next Monday.

BlackRock's Strange Numbers
It is curious that only two ETFs recorded inflows yesterday, despite the sector's positive performance. For Morgan Stanley, the 'novelty factor' is still at play, with many starting to invest in this ETF thanks to fees that are significantly lower than the competition.
For BlackRock, the situation is more complex: as volumes and open interest on Bitcoin grow, this ticker is also being used as a 'base' for other products—from options to other futures positions. Therefore, it might not be the result of a simple, pure long positioning.