What Is Put-Call Parity For Vertical Spreads?

The put-call parity formula isn't just for calls and puts. You can combine formulas to show for strategies--and interesting insights pop out. What is put-call parity for a vertical spread--and what does it show? Please join my Facebook group at this link:   / 290679008073523   And you can find my podcast from Market Rebellion at this link:    • Thinking In Options with Bill Johnson