Large investors, including Wall Street types and the new Bitcoin ETFs, tend to buy their coins discreetly from Over The Counter (OTC) brokers, rather than through the exchanges. But the OTC desks are running low. Here's the chart:
Who supplies the coins to the OTC desks? Mainly miners who need to sell a steady amount to pay for overheads like electricity, equipment etc.
As global energy costs come down, miners need to sell a lot less coins. Also, with the halvening coming up, some miners will be holding back coins in the hopes of a pump.
Meanwhile, demand from ETFs grows slowly but steadily.
When the halvening happens, supply will abruptly reduce. At that point the price should jump. Really, the ETFs came online at just the right time, boosting demand as the supply was about to be restricted. :-)