None of it has moved.
https://blockchain.info/address/15h6A2a3D31vRviBDdSpvhLtYJq3aePhdW
It shows about 17000 BTC being spent over the last few days
I think what he meant was that the coins that were transferred recently to different addresses haven't moved from those new addresses.
That shouldn't give reassurance to anyone... for all that is known, the coins were sold and you're looking at them sitting in the buyers wallet...
Just saying...