No, like promised by many members, nothing happened. 750 000$ is quite a "little" sum these days. Also, with the halving effervescence, it will be a grain of sand in the desert.
Yes nothing happened to move till now don't know either they really buy some bitcoins or not. But even if they have bought as bitcoin marketcap has already so huge that less than a million dollar couldn't alter the price now.
Market cap does not dicatate what happens when a relatively large amount of coins is bought in one chunk. It is the market liquidity that determines how much the price moves.
If the order books on the sell side are quite empty, a buy like this in one order on one exchange may still move the price tens of dollars. The order books are just not full enough to cover it.
Price will correct soon after though, as the buy support is not sustained and the gap between the buy and sell side will close again, but a termporary spike is still very likely and you might be able to profit of bots if you sell right after the buy due to them filling the empty orders between buy and sell.