Choosing the right broker is one of the most important decisions for any trader. Especially in AI trading, there are requirements that go beyond the standard depot. This guide helps you find the perfect broker for your setup.

The 5 Criteria for AI Trading Brokers

1. API Access

The most important criterion: Does the broker offer a stable, documented API? Without API access, you cannot automatically execute AI signals. Interactive Brokers offers the most mature API (TWS API), followed by Alpaca and CapTrader. Trade Republic and Scalable Capital do not offer full API access — here you must execute signals manually.

2. Order Execution and Latency

When an AI signal arrives, speed matters. The difference between the signal price and the actual execution price (slippage) eats into returns. Look for:

Direct market access: No market maker in between
Low latency: Under 50ms from order send to execution
Smart order routing: Automatic search for the best execution price

3. Fee Structure

AI trading generates more trades than buy-and-hold. Therefore transaction costs are critical:

Trade Republic: 1 euro per trade — cheap for few trades, expensive at 50+ per month
Interactive Brokers: From $0.01/share, minimum $1 — ideal for active traders
Scalable Capital: Free Broker (0 euros via gettex) — good for ETF savers but limited exchanges

4. Product Range

The broader the offering, the more AI signals you can execute:

Stocks and ETFs only: Trade Republic, Scalable Capital
Stocks, ETFs, Options, Futures, Forex: Interactive Brokers, CapTrader
Crypto integration: Trade Republic (limited), Bitpanda, eToro

5. Regulation and Security

Your capital must be safe. Non-negotiable:

BaFin regulation (Germany) or equivalent (FCA, SEC)
Deposit insurance up to at least 100,000 euros
Segregated client accounts (your money separated from broker assets)

Our Recommendation by Trader Type

Beginners with small budget (under 10,000 euros): Trade Republic or Scalable Capital. Low entry barrier, user-friendly, but signals must be executed manually.

Active traders (10,000-100,000 euros): Interactive Brokers via CapTrader (German support). Full API access, professional tools, fair fees at high volume.

Professional traders (100,000+ euros): Interactive Brokers directly. Lowest fees at high volume, access to all global markets, FIX API for maximum speed.

Bottom Line: There is no perfect broker for everyone. But with the right criteria, you can find the one that fits your budget, experience level, and trading style.