There was about 128,000 in volume, Assuming worst case scenario, it appears that the compensated loss would be ~$40 million dollars. If you assume buy limit order book was triangular it's about ~$25 million dollars. That's about 100-200 days of ether trading fees.
This really depends on how many stop loss orders were there and how users are refunded. I.E. will people be refunded in current price of ethereum or in the amount their stop loss order was set to be executed on?
Not off the shelf, no, not to my knowledge. This would probably fall under some kind of liability insurance contract and there are plenty of companies that would structure it for you. However, it would be a very complicated and expensive contract with the insurers demanding lots of financial and security audits as well as due diligence by field experts.
I've worked on an insurance deal in aerospace with an unproven launch vehicle and from where I was siting, it was just a guessing game based loosely on existing data and some invasive due diligence. These deals work because the insurance company is itself insured by other companies that spread the risk around enough that even a claim for the maximum amount wouldn't do much worse than wipe out a few months profit. No one insures for such large amounts with small unproven companies so the biggest risk for both parties is a systemic failure like AIG.