Quote from sle:
It's much simpler. A binary option is perfectly replicated via a call spread, that's how a dealer hedges. The bid/offer on the digital is determined by the width of the call spread and the direction of the barrier shift.
Well, they are pricing a digital by pricing a tight call spread, but don't always hedge it. When I was running an exotics book, I would only hedge really large digital risk (e.g. 100m in size) and smaller stuff I would just throw into the book (it is actually booked as a call spread) and delta-hedge.Quote from cdcaveman:
so your saying that a binary is exactly a call spread but more expensive because they are making a spread between them buying a call spread and them selling you a binary.
Oh, nobody exactly replicates each and every tiny digital, that would be silly. The market maker trades them and hedges delta, if the call spread width is wide enough, you will statistically make money. However, if digital risk on any strike is too high, we can always offset it in vanilla options, not necessarily of the same maturity.Quote from obsidian:
Where are they trading daily-expiry calls/puts on indices?
Quote from sle:
Well, they are pricing a digital by pricing a tight call spread, but don't always hedge it. When I was running an exotics book, I would only hedge really large digital risk (e.g. 100m in size) and smaller stuff I would just throw into the book (it is actually booked as a call spread) and delta-hedge.
Oh, nobody exactly replicates each and every tiny digital, that would be silly. The market maker trades them and hedges delta, if the call spread width is wide enough, you will statistically make money. However, if digital risk on any strike is too high, we can always offset it in vanilla options, not necessarily of the same maturity.
Quote from obsidian:
Is there a substantial interbank/brokerdealer market for short-dated digital (binary) options on equity indices? I was wondering how a larger dealer like igmarkets would be hedging their risk typically or if they just warehouse it like a casino would.
Quote from southall:
They monitor P/L on each market and increase the bid/ask spread until it is profitable for them. Binaries started out many years ago with smallish spread, about 2%, now some markets are 6% and some even 9% wide.
They also know who they are betting against and will back away from their prices if a big punter with a profitable history tries to hit them in a fast moving market.
So no hedging but they rely on a few dirty tricks to ensure they are profitable at market making these instruments.