How to Calculate Margin Interest on Tiger Brokers for SGX Stocks

Margin interest is the cost you pay to borrow funds from your broker when you buy stocks on margin—essentially, an interest charge on the loan used to fund your position. As of the latest fee schedule, Tiger Brokers charges a tiered annual interest rate for SGD-margined SGX stocks, starting at 4.88% p.a. for debit balances under S$50,000. This article breaks down the exact formula, shows a real-world example with numbers, and compares Tiger’s rate against key competitors so you can see your daily borrowing cost at a glance.

Understanding Tiger Brokers’ SGD Margin Rate Tiers

Tiger Brokers applies a blended rate that gets cheaper as your SGD debit balance grows. The current tier structure for SGX stock margin loans is:

• < S$50,000: 4.88% p.a.
• S$50,000 – S$200,000: 4.38% p.a.
• > S$200,000: 3.88% p.a.

The rate applies to the entire debit balance, but only the portion that falls within a higher tier benefits from the lower rate. Interest accrues daily on your outstanding loan amount (not the total position value) and is computed in SGD even if you hold dual-currency stocks – all SGX counters are margined in Singapore dollars.

The Daily Margin Interest Formula

Tiger Brokers calculates interest daily using a 365-day year. The formula is:

Daily Interest = (Debit Balance × Annual Rate) ÷ 365

If you hold a position for multiple days, you simply multiply the daily figure by the number of days the debit balance is outstanding. Weekly and monthly totals can be projected the same way. The broker posts the accrued interest to your account monthly, usually on the last business day.

Example Calculation: Buying 1,000 DBS Shares on Margin

Let’s say you want to buy 1,000 shares of DBS Group Holdings (SGX: D05) at S$33.50 per share. Total position value = S$33,500.

• Initial Margin Requirement (IM) for DBS, a blue‑chip SGX stock, is typically 25% at Tiger Brokers.
• Your required cash outlay = 25% × S$33,500 = S$8,375.
• Broker finances the remaining balance: S$33,500 – S$8,375 = S$25,125.

Because your debit balance of S$25,125 falls entirely in the < S$50,000 tier, the annual rate applied is 4.88%.

Daily interest = (S$25,125 × 0.0488) ÷ 365 = S$3.36 per day.

If you hold the position for 30 days, the total margin cost would be S$3.36 × 30 = S$100.80.

Factors That Can Change Your Effective Rate

• Currency of the loan: Margin rates for USD‑denominated positions are higher (Tiger’s USD margin rate starts at 6.8% for balances under US$25,000). SGX stocks always settle in SGD, so the SGD tier schedule applies automatically.
• Crossing a tier boundary: Once your total SGD debit balance moves above S$50,000, the extra amount gets the lower 4.38% rate, reducing your blended cost. For example, a S$70,000 debit balance would be charged 4.88% on the first S$50,000 and 4.38% on the next S$20,000.
• Margin call risk: If your equity falls below the maintenance margin, Tiger may force‑liquidate positions. Interest keeps accruing on any remaining loan until settled.

How Tiger Brokers’ SGD Margin Rates Compare

I benchmarked Tiger’s posted SGD margin rates against two other popular platforms used by Singapore traders, assuming a S$20,000 debit balance. Daily interest costs are computed with the 365‑day formula.

Broker	Standard Rate for S$20k SGD Loan	Daily Interest
Tiger Brokers	4.88% p.a. (first S$50k)	S$2.67
Moomoo SG	6.8% p.a. (standard account)	S$3.73
Interactive Brokers	SGD benchmark + 1.5% (~4.8%)*	~S$2.63

*Based on the current SGD Overnight Rate of ~3.3% plus IBKR’s tier‑spread of 1.5% for balances under S$130,000.

Tiger’s base rate is nearly 1.92 percentage points lower than Moomoo’s standard offering and tracks very close to Interactive Brokers’ institutional‑grade pricing. Moomoo does offer discounted VIP rates (as low as 4.2%) but requires higher asset thresholds and active trading volume to qualify.

Tips to Minimise Margin Interest Costs

• Borrow only what you need – keep your debit balance as small as possible and avoid leveraging up to the full initial margin limit.
• Use limit orders to control your entry price and prevent accidental over‑leveraging from market orders that can slip.
• Pay down the loan quickly – Tiger does not charge prepayment penalties. Even partial repayments immediately reduce your daily interest charge.
• Monitor utilisation inside the Tiger app. Crossing a tier boundary upward can actually lower your blended cost, but avoid letting a small debit balance drift just under a cutoff if you can consolidate.

Historical Comparison: Margin Rates in 2022 vs 2025

To highlight how dramatically the interest‑rate environment affects margin costs, here is the same S$25,125 DBS loan computed with Tiger’s rate from 2022, when the SGD Overnight Rate was near zero.

Period	Annual Rate	Daily Cost (S$25k loan)
2022	1.50% p.a.	S$1.03
2025 (current)	4.88% p.a.	S$3.36

The cost of carrying the same margin position has more than tripled in three years. This underscores that timing your use of leverage relative to the interest‑rate cycle can have a material impact on returns.

FAQ

How often is margin interest charged on Tiger Brokers?
Interest accrues daily and is deducted from your account as a single line item at the end of each calendar month. The daily interest will appear in your transaction history as “Margin Interest” once it is posted.

Is margin interest tax‑deductible for Singapore retail traders?
Generally no. Under IRAS guidelines, interest expenses on share margin are only deductible if trading is conducted as a business. Retail investors who do not qualify as professional traders cannot claim this deduction. Always consult a tax professional.

Does the margin rate change depending on which SGX stock I hold?
No. Tiger Brokers applies the same SGD tier rates to all SGX‑listed equities. The only factors that alter the rate are your total SGD debit balance and your account tier (e.g., Prime vs standard). Some structured products or foreign‑listed securities may have different rates, but all straight SGX equity positions are treated uniformly.

What happens if I cannot cover the interest charge?
Unpaid interest gets added to your debit balance, increasing the principal on which future interest is calculated (compounding effect). If the accumulated debit drives your equity below the maintenance margin threshold, you will receive a margin call and must deposit additional funds or sell securities to restore the required margin ratio.

参考资料

1. Tiger Brokers Singapore – Official Fee Schedule (Prime Margin Rates for SGD).
2. SGX Margin Requirements for Individual Counters.
3. Interactive Brokers Singapore – Interest Charged on Margin Loans.
4. IRAS – Tax Treatment of Interest Expenses for Individuals.

This article does not constitute financial advice.