I think the other factor to keep in mind is that Bitcoin is still wildly inflationary, much more so than USD.
Each day 3200+ coins are minted, and at $500 price tag, requires $1.6M new money to enter the Bitcoin economy, every single day, just to maintain the $500 price tag.
When less than $1.6M enters, price -> fall. Until a new equilibrium is reached.
On the other hand, if more than $1.6M enters each day, then price will rise.
That's a good point.
But there's also 2 things on top of that:
1) If less than 1.6M of bitcoin is bought in a day, it doesn't automatically mean that prices go down. Because all bitcoin miners don't sell their new minted coins right away. Many of them just hold them.
2) When next halving occurs, it will be 0.8M, much less. So this means that the more halving events we have, the quicker the price will start going up in the future.