You have to read the terms and conditions to know for sure.
Iirc they give a date that they check how much is in the account.
I also think you have to leave it in for 6 months or you risk a clawback.
From their website:
"You have 45 days from the date you become a new client and enroll in the offer to make a qualifying net deposit; note – you must deposit the qualifying amount in the account that you enrolled in to be eligible.
When will I get my reward?
All rewards are paid out to qualifying clients about 1-2 weeks after the 45 days eligibility period ends, regardless of when you make the deposit (as long as it's in the first 45 days).
Two examples:
You sign up and enroll March 1st. Even though you make a qualifying deposit March 15th the promotion will "read" your net deposits at the 45 day mark (around April 15th), and process your award. Payment will be made 1-2 weeks after, around April 25th.
You sign up and enroll March 1st. You make a qualifying deposit on April 10th,the promotion will "read" your net deposits at the 45 day mark (around April 15th), and process your award. You award will be posted approximately April 25th.
Why should I deposit sooner rather than wait for the 45 days if my reward gets paid out at the same time?
We wanted to provide an amount of time to deposit that didn't feel rushed. Many of our clients make multiple deposits within the qualifying period to "level up" to the next reward tier. Also – it is always good to get invested sooner."
Sounds from all this that as long as you deposit that amount before the 45 day deadline it will work. It also seems like it is NET deposits so withdrawal will deduct if within the timeframe.