Delta of 50

Discussion in 'Options' started by Herkfsu, Aug 31, 2018.

  1. Herkfsu

    Herkfsu

    Hello,

    Do options only have a delta of 50 if the FORWARD price is at the money? I believe there is a residual amount which is influenced by vol(please correct me if I am wrong).

    Thanks!
     
  2. guru

    guru

  3. destriero

    destriero

  4. Wow...I get to answer this twice today.

    No, only if they are European style exercise. American style exercise always have parity / early exercise as a backstop to value.

    No-arbitrage sets the option chain prices--periods of extreme illiquidity notwithstanding--ATM American style must have 50-delta. (This need not be constant, but the market will reconcile it in time).
     
  5. sle

    sle

    You belief is right. As the vol goes higher, ATMF delta goes towards the call. It's pretty intuitive if you take it to the volatility to the infinite limit (*) - a stock price can go to infinity but can only fall to zero, so call delta should dominate.

    * e.g. a world where all rulers are like our Supreme Leader
    PS. I assume when you say "FORWARD" in all caps, you mean a forward price derived from a price of a European combo or an actual quoted futures/forward price
     
  6. Herkfsu

    Herkfsu

    So what would cause a stock like TSLA to have a delta of 56 on a 90d ATM call? Risk free rate and high vol?
     
  7. Herkfsu

    Herkfsu

    I just meant forward as opposed to spot price. Not sure what a european combo is, but I always thought equity forwards were priced using Rf and dividends. Is that not always the case?
     

  8. Secret Santa wins.

    In high vol products, especially noticeable in over 100 IV, ATM calls will have significantly higher delta than ATM puts.
     
  9. Edit: for completeness sake, Secret Santa is correct also. the market will tend towards 50-delta....not necessarily achieve it.
     
    Last edited: Sep 11, 2018
  10. No, there is usually an ATM delta difference between call and put. This is true in front month as well as vs forward values in longer term expirations. Only in super low vol products (like SPX) will you see close to 50:50 atm p/c delta ratios.

    The delta difference increases as vol increases.
     
    #10     Sep 11, 2018