Calculation formula: the amount of N lots of margin occupied by a futures contract = settlement price of the day × trading unit (contract multiplier) × futures margin rate ×N lots.
Suppose an investor has three operations on rebar futures varieties (assuming the rebar margin ratio is 9%):
1.8 lots of rebar (1705) were bought on February 5th, and the transaction price was 3 150, so the frozen deposit was 3150×10× 9 %× 8 = 22680.
2. On February 5th, 3 positions were closed, and the transaction price was 3,200, so the release margin for closing positions was 3,200×10× 9 %× 3 = 8,640.
The deposit occupied by the other five positions: 3150×10× 9 %× 5 =14175.
After settlement, the settlement price of the day is: 3 198. Then according to the settlement price, the position deposit should be: 3198×10× 9 %× 5 =14391> the deposit actually occupied before settlement is 14 175. At this time, the insufficient part (14391-14175 = 216 yuan) will be transferred from the available funds in the futures account to the trading margin freeze.
Two, there are two kinds of margin:
One is the settlement reserve, which is what we usually call available funds. It is the funds that investors prepare for trading settlement in futures accounts in advance, and it is the deposit that is not occupied by contracts. For example, this part of the funds is used by traders when they open new positions.
The other is trading margin, also called margin occupation, which is the fund to ensure the performance of the contract and the margin that has been occupied by the contract, that is, this part of the fund has been frozen and cannot be used, that is, it cannot be used to build a new warehouse.
Third, because the futures traded by investors are different, the price of futures will change at any time, so the margin will also change with the change of futures price. Investors only need to know how to calculate the trading margin, and then calculate the margin according to the futures they want to buy to see if it meets their expectations.
The proportional margin system is the trend of market development, because it can keep the risks of futures companies and exchanges at a certain level all the time, while the fixed margin system can not meet such requirements. If the fixed margin system wants to ensure that the risks of exchanges and futures companies are always within the controllable and acceptable range, only by setting the original margin high enough to make the index fluctuate at the highest level that can be expected can the customer margin still be guaranteed to be no less than a certain order of magnitude (for example, 6%). When the index is at a low level, the utilization rate of market funds is low, which leads to the decrease of market efficiency. The solution to this problem is that the exchange adjusts the size of the fixed margin according to the level of the index, but this involves new efficiency problems, because the index may rise to a higher level soon after lowering the margin level, forcing the exchange to adjust again in the short term.