You presume that when I buy shares of SPNG, I am buying those shares from another shareholder who is selling. That is not the case. I am buying the shares from a MM's inventory.
If shareholder sells shares, that shareholder is selling those shares to a MM.
With that in mind, the stats
BUYS 31.5 million shares
SELLS: 25.4 million shares
Mean that 31.5 million shares were bought from the MMs and 25.4 million shares were sold to the MMs.
From that, one can see that the MMs had to supply 6 million +/- shares from their inventory, or go short to fill the buy orders.
¶ No, that's not how it works. Every buy has a matching sell and ever sell has a matching buy, or you can call it simply: a trade.
Dr. Egon Spengler: Don't cross the streams.
Dr. Peter Venkman: Why?
Dr. Egon Spengler: It would be bad.