Up again. Now 36 million. I don't understand it. Just keeps increasing.

It probably ACAS holders hedging their position to protect their merger positions. From my standpoint as an ARCC shareholder it should create a floor going forward. A lot of those shorts will disappear as they are covered by ARCC shares received at the merger. Since the shorts have to pay the $0.38 quarterly divvies their might be a squeeze if the merger for some reason is delayed or cancelled.

b&w

There is still an arbitrage opportunity.

Back on 12/15 there was a 3.17% gain available to those who buy ACAS and sell (or short) ARCC. The values continue to converge, but at the 12/30 close, there is still another 0.97% gain left.

ARCC 12/20: $16.49
Implied ACAS value: $18.09
ACAS 12/30: $17.92
Arbitrage gain: 17c