How many prices have in practice option for put–call parity

Question

How many prices have in practice option for put–call parity?

Answer 1

In practice options do not have any single price; they consist of two prices, a bid and an offer or ask. It implies that when looking for violations of put–call parity you should use bid (offer) when you are going short (long) the options. It makes the calculations slightly messier. It’s much easier to spot violations of put–call parity, if you think in terms of implied volatility. You should look for non-overlapping implied volatility ranges.