Deciphering a Complicated Formula to Calculate Peak to Trough Change

Hi,

I have the following formula that calculates the Maximum Drawdown from a series of values in A3:A63:

{=MIN(IFERROR($A$3:$A$63/SUBTOTAL(4,OFFSET($A$3:$A$63,-1,,ROW(INDIRECT("1:"&ROWS($A$3:$A$63))),))-1,""))}

The Maximum Drawdown is the largest drop from peak to trough in a series of values.

Can someone please explain how the above formula works to calculate this?

Thanks!