CEA
China Eastern Airlines
stock NYSE

Yes, $100K buying power means you can only exercise 5 of the 50 (each $200 strike contract needs $20K to take delivery of 100 shares). The other 45 expire worthless.
You can't rinse and repeat. Exercise notices submitted before your broker's after-hours cutoff (varies by broker, usually 30-60 minutes after the bell; check yours) result in shares hitting your account on T+1, meaning next trading day morning. You don't actually receive the shares until market opens. So selling can't happen until then, and by then price could be anywhere including back below your $200 strike, leaving you with 500 shares of overnight gap risk.
Two mechanics worth knowing: the broker won't auto-exercise OTM contracts, so you must submit a Contrary Exercise Advice manually (IBKR calls it "Notice of Exercise"; Fidelity has a similar form). And the 4:00pm closing print is what determines auto-exercise behavior. AH moves don't change auto-exercise; only your manual CEA does. The safer play is exercising the 4-5 contracts your buying power allows and accepting overnight gap risk on those 500 shares. The other 45 are gone. Trying to fake-leverage by selling shares you don't yet own would get flagged by your broker.

Yes, $100K buying power means you can only exercise 5 of the 50 (each $200 strike contract needs $20K to take delivery of 100 shares). The other 45 expire worthless.
You can't rinse and repeat. Exercise notices submitted before your broker's after-hours cutoff (varies by broker, usually 30-60 minutes after the bell; check yours) result in shares hitting your account on T+1, meaning next trading day morning. You don't actually receive the shares until market opens. So selling can't happen until then, and by then price could be anywhere including back below your $200 strike, leaving you with 500 shares of overnight gap risk.
Two mechanics worth knowing: the broker won't auto-exercise OTM contracts, so you must submit a Contrary Exercise Advice manually (IBKR calls it "Notice of Exercise"; Fidelity has a similar form). And the 4:00pm closing print is what determines auto-exercise behavior. AH moves don't change auto-exercise; only your manual CEA does. The safer play is exercising the 4-5 contracts your buying power allows and accepting overnight gap risk on those 500 shares. The other 45 are gone. Trying to fake-leverage by selling shares you don't yet own would get flagged by your broker.