OK, can't I just SELL "350 @ $395 and BUY "340" @ $391 and pocket $4 immediately and realize another $10 if and when the counter party who bought "350" decides to exercise? I'm not bothering with a synthetic call arbitrage argument here, which, by the way, should yield $14 riskless profit. Can anyone please explain to me what's wrong with my reasoning or with the option chains?
Above is the snapshot for this Google January 2018 call.
The key to this OP's question is 2 fold. Stale quotes, as you can see the bid/ask nowhere near the last trade prices. And the low open interest.
Your reasoning fails in that the orders would never fill at those prices. The spread is so deep in the money it would sell for over $9, in my opinion, not give you a credit to trade.
Think of it this way, say there was no credit, but you could enter the trade at $1. You would get 10X your money if Google simply doesn't drop by half in 20 months.
Last - when you see these prices that make no sense, just enter an order. What do you have to lose? Of course, I mean an order you want to fill, like a $4 credit, or even $1 credit. You'll quickly see the bid and ask adjust for your order. (Which, if I'm back after the market opens, I might just do, and post that image. Done)
This is the bid/ask at today's open. The bid/ask spreads are wide enough, you'd never enter as a market order. It would fill at $10 or slightly under as a limit order.