Can someone explain the mechanism of how halving impacts bitcoin prices?

So far I've bought into the idea that the halving causes a supply shock, but now I'm not so sure.

According to the metrics roughly 900 BTC are mined each day, which is roughly $30M/day.

Meanwhile the daily trading volume is roughly $15B/Day.

Assuming all mined coins are sold the day they are mined, this represents 0.2% of the daily trading volume. At halving this would reduce to 0.1%.

How does a reduction of 0.1% of supply have any effect at all?

What am I missing?