Learn · Leverage and risk
Margin: borrowing City Coin
How financing changes buying power, creates interest and adds an account Maintenance line.
Last updated: 2026-09-20
Financing starts with an account setting
Ordinary purchases in MockTradeCity are funded from your own available City Coin. Margin mode is off by default. Enabling it in Account opens a confirmation showing the engine's current initial margin requirement, interest rate and maintenance rules. The setting permits eligible stock purchases to use borrowed CC when available cash is insufficient. It does not turn every purchase into a financed one or add a reward to your account equity.
Borrowed CC comes from the city's financing pool and creates a recorded debt. You cannot remove that debt by turning the setting off: disabling margin is blocked while financing remains unpaid. The entire mechanism is fictional, with no real currency advanced and no real brokerage credit agreement. Within the simulation, however, the liability matters to buying power, account equity and maintenance in the same concrete way that a share position matters.
Buying power depends on the whole account
The current initial margin requirement is sixty percent, corresponding to roughly 1.67 times unencumbered cash for a fresh account without other positions or debt. As an illustration, 6,000 CC can support about 10,000 CC of eligible exposure under that simplified starting condition. The engine's actual buying-power calculation also considers existing long Market value and outstanding principal. It is therefore more specific than multiplying whatever cash number happens to be visible by a fixed factor.
A purchase within available cash does not need a financing draw. Only the eligible shortfall is borrowed, reserved for the order and recorded as principal. A request beyond the account's available buying power is rejected. Finite pool resources and ordinary order checks still apply. Borrowing and reserving the money are accounting events tied to the order; neither provides permission to spend the same borrowed amount again while its first commitment remains open.
Interest and repayments follow account events
The published financing rate is currently six percent annually, charged on a daily basis. The interest-day boundary is 4:00 p.m. in New York. A day's charge uses principal times the annual rate divided by 365, subject to the engine's monetary precision. Available CC pays the charge first. Any unpaid portion rolls into principal, which means subsequent interest can include that added debt if it remains outstanding.
CC returning to the account is applied through the repayment rules. A sale or released order reservation can therefore reduce debt instead of leaving the full returned amount as Available CC. This explains why canceling a financed purchase may not produce the cash increase a cash-only account would show. Accounts with unpaid financing cannot use that condition to fund IPO subscriptions or Lifestyle purchases; those paths require the applicable debt restriction to be cleared.
Maintenance is checked after opening
An initial requirement controls entry; a Maintenance line controls the continuing account. The current long maintenance rate is fifty percent. In a simplified account containing only financed long shares, a position worth 10,000 CC with 4,000 CC debt has 6,000 CC equity against a 5,000 CC maintenance requirement. If that position falls to 7,000 CC with debt unchanged, equity becomes 3,000 CC against a 3,500 CC requirement.
When the applicable account test falls below maintenance, the engine can sell long holdings to repay financing without another reminder, starting with the largest long Market value. Mixed long-and-short accounts also have short-side requirements and covering behavior. Liquidation uses normal market execution and protection rules, so a thin book or trading restriction can prevent full completion in one round. The starting amount of your own CC is not a guaranteed limit on simulated losses.
Where to inspect financing in the city
Account displays the margin setting, outstanding financing and buying-power figures. The confirmation panel reads parameters from the engine, which makes it the relevant source if a future rule change differs from an old numerical example. Activity records distinguish draws, repayments and interest. Positions supplies the long values used in the account picture, while the net-worth breakdown keeps liabilities visible rather than presenting borrowed funds as if they were new wealth.
The Season leaderboard marks accounts with margin mode enabled so readers can interpret performance with that setting in view. That badge does not disclose every trade or guarantee that borrowing was used continuously. Market rules explains the financing and short-sale requirements separately. Reading the current debt, maintenance requirement and available resources together describes the actual account state more accurately than focusing on the setting alone or treating the maximum purchasing figure as a spending balance.