I can't speak of the cost for institutions who may be doing a...

I can't speak of the cost for institutions who may be doing a pure arbitrage plays. (Obviously professionals will only put these type of plays on if its profitable - it's not guess work)

However, consider a smaller investor who owns say 10,000 shares in OSH.

If they sell on market @ $4.50 ... receive $45,000. (they may have bought at $2.50 or $3.50 or $4.50 for all it matters)

Instead if they short 6275 STO, they are getting $4.63

$1300 Additional profit, and lock out exposure to price movement.

Brokerage fees for establishing a short via warrants or CFD is modest ~ ranges from as low as $10 to $40 for combined cost of opening and close the short.

The spread may close in 1 day, 1 weeks or 2 months time... a daily carry cost charge can be calculated... And a likely maximum cost of carry if the dates of conversion of OSH to STO are known. - so you can work out if profitable enough.

So, the point is every shareholder can receive the advantage of the arbitrage that currently exists.

DYOR folks...

Enough from me on this topic - all i was doing was point out that bigger short positions may not be people taking bearish bets.