Basic Points

• The Key Delta Strike has the largest delta.
• This level is found in the Equity Hub under the Composite View and the Put & Call Input tab
• In general, this is one of the major key levels of support and resistance. The other two of its kind–that can be found in between the Put Wall and Call Wall–are the Key Gamma Strike and Hedge Wall. 

Intermediate

The main dynamic at play here is that, the further out-of-the-money a strike is, the less delta it has. Therefore, a strike would require more and more open interest when further out-of-the-money to qualify as the Key Delta Strike. 

Another dynamic is that if a stock is dominated by calls, as shown by all green in the shaded example below with AAPL, then the Key Delta Strike can be below the Put Wall as a result of the heavy use of ITM options. Likewise, with a stock dominated by puts, such as MSFT shown below in all red, the Key Delta Strike can be above the Call Wall as a result of many ITM puts at that level.

<SpotGamma Equity Hub Composite View for APPL>

<SpotGamma Equity Hub Composite View for MSFT>