My understanding is that the new regulation sets the upper limits for margin for pattern daytraders. A broker can allow up 4X margin. But if the broker wants to be more conservative, and give you less margin, they can do that too. They just cannot give you more margin than the reg allows.
I could be wrong, but I think that is how it works. I don't know why a broker would drive customers away by offering LESS margin than they are allowed to do.
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