Well, isn't the Sabbath from sundown Friday to sundown Saturday? Which on the USA east coast means that basically she is a full-timer. Markets close on Friday pretty much at sundown, and reopen 48 hours later on Sunday. Basically.
The lady trader is in Phuket Island, Siam.
Therefore her Shabbat would arrive
13 hours ahead or before EST.
e.g. It is now 9.11 am EST Monday morning
in the U.S.,
in Siam, it is already 8.11 pm in the evening
of Monday.
So comes your EST Friday morning, it already
encroaches upon the Shabbat evening in Siam.
SHALOM everyone.