Core terms
Offshore broker
A brokerage organized and regulated outside the US that offers trading in US-listed stocks. It is not a FINRA member, so US investor protections such as SIPC coverage and FINRA arbitration generally do not apply.
Traders have used offshore brokers mainly to avoid the old pattern day trader rule or to get higher leverage. The trade-off is protection. SIPC protects customers of SIPC-member broker-dealers when a firm fails; it does not cover a non-member firm. Disputes go to the courts or regulators of the broker's home country, not to FINRA.
Some offshore firms route orders through US brokers, so execution can look the same. What differs is who holds your money and which rules apply if something goes wrong.
What traders should verify
Check the firm's regulator and registration in its home country, how client money is held, and how you would recover funds if the firm failed.
Do not conflate
FennEdge does not rate brokers. FINRA's BrokerCheck covers only US-registered firms and individuals.