Im sorry but I just can't believe you just bought 10K BTC like it's nothing without providing any proof. IF you are going to go as far as saying it on a public forum, you could at least provide some sort of evidence.
He didn't buy 10k BTC, he bought a 10k BTC Put option.
Are there reliable(or half-reliable) sites to trade btc options?
There's coinut.com but you won't get anything close to that amount of volume.
You'd need to make OTC deals.
I wonder what would happen if the coin price moves in the other direction. I'm sure you have all the plans put in place in case the result did not turn out as what you expected? By the way, just wondering where did you manage to secure that amount of funding? Kind of curious since that is not small amount by any means.
If it doesn't turn out he loses $75 000. If it does turn out he'll make $75000 for every $7.5 the price goes under 207.5.