To refresh: Basis = Future(bid) - Spot(ask)
For the first two and half hours, the spot price is not moving. So, the only way the basis can drop is if the price of the September silver future is dropping. In other words, selling of futures. But while that was going on, there was enough buying of spot to keep it steady.
Then, perhaps some market participants became aware of the buying of spot. Or perhaps some other buyers got excited. Somebody was buying in size, because between around…
