'bid' and 'ask' are often 0, in an inconsistent pattern

[gusl]

call = Call('SPY', d=18, m=12, y=2020)
print(call.strikes[30:40])

call.set_strike(211)
print(call.ask)
call.set_strike(212)
print(call.ask)
call.set_strike(213)
print(call.ask)

Output:

(205, 207, 208, 209, 210, 211, 212, 213, 214, 215)
0.0
79.43
0.0

This seems to happens mostly at night, when the market is closed.

[andyslater]

same for me too

[windrider09]

That happens to me way after market hours.