Why is there initial margin when I did not borrow any money to begin with?

External question — Personal Finance Stack Exchange Author: Aurora Borealis Original post: https://money.stackexchange.com/questions/165577 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. I have a margin account, and I deposited around 1,010,431.16 HKD buying power of cash into my margin account (all of which I used to buy stocks). My stocks went down lately so the Market Value is now 894,853.05 HKD. I have used solely the cash I have deposited into my margin account, yet in my risk level it says: leverage ratio 0.99, excess liquidity: 608,055.82 HKD, initial margin: 390,296.07 HKD and maintenance margin: 286,999.09 HKD. What is this margin? I do not recall borrowing any money but it seems to give margin which is confusing to me. Can anyone explain why my initial margin isn't 0, and shows those values even though I have not borrowed any money to buy the stocks from my brokerage app?

External answer — Personal Finance Stack Exchange Author: nanoman Original post: https://money.stackexchange.com/a/165578 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. Although "margin" is often used colloquially to mean borrowing, technically margin is sort of the opposite: the amount you are required to put up yourself instead of borrowing. It makes sense because what you put up yourself is the "margin of safety" for the broker (the amount your investments can lose before the broker's own funds are at risk). Here the broker is telling you that from your 895k account you could withdraw in cash (without selling any stocks) up to 608k! This would leave your "skin" in the account at the minimum level of 287k. If you did this and your stocks declined any further, your account would be called/liquidated to protect the broker.