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Trading Costs You Must Calculate Before Investing: Sub-brokerage vs Overseas Brokers

Wanting to trade US stocks in Taiwan means facing two critical questions: which route to take, and how much will it cost? This is no small matter — buying the same $1,000 worth of US stocks through different methods could cost you double.

Investors typically have two choices: using domestic sub-brokerage services or trading directly with overseas brokers. However, these two paths have completely different fee structures and significant differences in hidden costs. This article uses real numbers to clarify the true differences between sub-brokerage fees and overseas brokers.

What is Sub-brokerage? Why Are the Fees Higher?

Sub-brokerage (Sub-Brokerage), formally known as “agent trading of foreign securities business,” simply means you entrust a domestic broker to buy US stocks on your behalf. Because your order must go through the domestic broker to reach US markets, it adds an extra layer, hence the name “sub” brokerage.

The advantages of this method are clear:

• Transact directly in New Taiwan Dollars without personally exchanging to USD; the domestic broker handles it
• Regulated by Taiwan’s Financial Supervisory Commission, providing dispute resolution protection
• Simple account opening without dealing with complex overseas banking processes

But there are drawbacks — complex procedures mean higher fees. Sub-brokerage commissions typically range from 0.15%～1% of transaction amount, already several times higher than overseas brokers.

US Stock Brokers’ Logic: Direct Trading, Lower Commissions

In contrast, overseas brokers function like domestic brokers in Taiwan — you open an account directly and place orders for US stocks yourself. Without intermediaries, the process is shorter, so commissions can be kept very low — most major brokers now offer zero commission or near-zero rates.

But there’s no free lunch. The trading commissions you save, you must handle yourself through currency exchange and wire transfers, which isn’t cheap either. Just wiring from Taiwan to overseas can cost NT$100～NT$900, plus exchange fees. For small transactions, these hidden costs can eliminate your savings advantage.

What Does Sub-brokerage Commission Include? Understand It to Avoid Being Overcharged

With sub-brokerage trading, you pay two types of fees:

First type: Directly charged by brokers

• Trading commissions are the main expense, typically 0.25%～1%, but each order has a minimum charge, usually $25～$100 USD. For example, buying $1,000 worth of stocks at 0.3% fee is only $3, but with the $25 minimum, your actual cost jumps to 2.5% — a 10-fold difference!
• Other miscellaneous fees such as wire transfer fees, paper statement fees, etc. (depending on each broker’s policy)

Second type: Hidden costs This is what’s easily overlooked. Exchange fees are collected by the US Securities and Exchange Commission (SEC), charged only on sales, at 0.00051% of transaction amount. Trading activity fees (TAF) are collected by the Financial Industry Regulatory Authority (FINRA), also charged only on sales, at $0.000119 per share, maximum $5.95. These are typically embedded by sub-brokerage brokers directly in their commissions.

Additionally, if stocks pay dividends, you must pay 30% withholding tax regardless of which method you use (some can be recovered).

Overseas Broker Trading Costs: Currency Exchange and Wire Fees Are the Main Expenses

Overseas broker trading costs have a completely different structure:

• Trading commission: Most major brokers now charge zero
• Financing interest: Only occurs if you use margin (borrowed money) to buy stocks
• Currency exchange fees: Charged by banks when converting TWD to USD, typically 0.05% of wire amount, but with minimum fees (usually NT$100～NT$600)
• Wire transfer fee: Cost of sending money from Taiwan to your overseas broker account, varies by bank, approximately NT$100～NT$900
• Withdrawal fees: Some brokers charge $10～$35 for withdrawals

Combined, small transactions can actually be more expensive than sub-brokerage.

Below is a fee comparison table for both methods:

Major Sub-brokerage Fee Summary Table

Below are 2025 fee standards for mainstream sub-brokers (each may adjust anytime; actual fees per latest official announcements):

Overseas Broker Fee Comparison Table

Bank currency exchange and wire fee reference (in New Taiwan Dollars):

Real Case Study: When Is Sub-brokerage Worth It, When Should You Use Overseas Brokers?

Using the cheapest combination available:

• Sub-brokerage: Fubon Securities (0.25% commission, minimum $25)
• Overseas broker: Mitrade (zero commission)
• Currency exchange: Bank of Taiwan (0.05% fee rate, minimum $100 wire fee, $200 wire charge)

Assuming exchange rate of 1 USD = 30 TWD:

Key Findings:

• Under $6,000: Sub-brokerage is cheaper (or similar)
• Over $6,000: Overseas brokers are significantly better

But this conclusion assumes you only trade once. If you trade 4 times (buy and sell twice each) with the same $10,000:

• Sub-brokerage costs $100 ($25×4 times)
• Overseas broker still costs $11.67 (wire is one-time; future trades are zero-fee)

The conclusion is clear:

• Small capital, infrequent trading → Sub-brokerage is cheaper
• Frequent trading → Overseas brokers have overwhelming advantage
• Large capital → Use overseas brokers directly; commission difference is significant

Which Path Should You Choose? Make a Rational Decision This Way

Sub-brokerage advantages apply to:

• Small capital ($1,000～$5,000)
• Infrequent trading (a few times per year)
• Don’t want the hassle of personal currency exchange
• Need Chinese language customer support

Overseas broker advantages apply to:

• Adequate capital base ($6,000+)
• More frequent trading
• Willing to handle currency exchange and wiring yourself
• Want to use leveraged financing

Mitrade as an overseas broker representative is authorized and regulated by Australia’s Securities and Investments Commission (ASIC) (License #398528), with account opening streamlined to just 3 steps:

1. Register: Submit information and application
2. Deposit: Minimum $50 USD required (supports TWD trading)
3. Trade: Identify opportunities, place orders in real-time

Regardless of which path you choose, remember this logic: understand the cost structure clearly, calculate total fees, and choose based on your trading habits and capital size to get the best value.

Quick Summary

• Sub-brokerage fees consist mainly of trading commissions, minimum fees, and hidden exchange fees; overall costs are higher
• Overseas brokers have low or zero trading commissions, but currency exchange, wire transfer, and withdrawal fees are hidden costs to consider
• Sub-brokerage suits small, infrequent trades; overseas brokers suit large, frequent trades
• Trading US stocks with different methods can save multiple times your costs by choosing correctly
• Before deciding, calculate all sub-brokerage fees AND all overseas broker costs; don’t look at only one fee component