> 3. Every strategy can be viewed as a sort of 'arbitrage'.

No, it can’t. This is a bastardization resulting from the proliferation of “stat arb” to mean mispricing and is truly a misnomer.

We have a running joke at work that our attempts at making money are "probabilistic arbs".

You're right. I was 100% thinking of 'stat arb' when I wrote that comment. What I meant to say that the way 'arb' is used is completely meaningless.

Maybe a clearer comment would have been:

"If rentech's strategy can be considered an arb, then every strategy can be considered an arb".

> "If rentech's strategy can be considered an arb, then every strategy can be considered an arb".

Yep, agreed.