I agree that this is SBR shop and they can do as they want. Still, I do not understand why they are taxing the transfer. They control both creation (points awarded daily) and redemption (prices at the store). They could adjust either side easily.

However, looks like they have trouble with their black hole of points (casino and sportsbook) not sucking off enough points of the system. There are two reasons: the product is not good enough (casino arguably rigged, sportsbook with full vig and without many options) and strong competition from Mex and other books.

In practice, Mex book is slightly about even, so the problem is not his points hedging, most possibly the problem is not getting the points disappear via the sportsbook. So, they choose to tax transfers, making harder for private book to survive.

However, the lenders are also badly affected. Loaning 100 points and being immediately paid costs 4%. So, there will not be many loans now. Many of such loans ended in SBR sportsbook, so they may get less action from that side.

In short, I do not see the real positive effect for SBR in this tax; there are better and easier options to devalue the points, without upsetting the users.