Hi, when I run the Z13 strategy with the selling naked put option, the option was several time every day exercised by the buyer. i have noticed, that the proposed option to sell has negative extrinsic value, so it seems to me the buyer can theoretically win by exercising the put option immediately and selling the underlying (especially some big traders with low fees). The run of Z13 :

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[146: Tue 23-05-16 00:00] 412.35/412.35\412.35/412.35 -0.01
NY time 14:35
!Get Option Chain SPY-OPT--0.00--SMART/ISLAND--USD
Chain of 7626 SPY contracts
Find 42 days put -443
{SPY::sP14602} Write 1 Put 20230630 442.0 100@29.09 Leg 1 Unl 412.45 at 00:00:00 Tue
Com 0000 Mrg 0000 Net 0 Prem 2909
Done!
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The value of 442 Put is just 29,09 with the SPY market price 412,45 , I assume for the buyer it is possible to excersize imediately and have 46 USD brutto profit ?

Should not be there some check in the Z13 strategy to avoid selling options that have zero or negative extrinsic value ?