Skip to main content

ELI5: ECN Fees



You're new to investing, have done your homework and is ready to get started. You find a discount brokerage offering commission-free ETF purchases. Perfect! You'll save a ton on fees. You enter in your first order and to your dismay, a fee! ECN? What is this? I thought there were no fees?

Commission-Free Doesn't Mean Free?

There's a misconception that commission-free trading equals to no-fee trading. A commission is the cost of facilitating and executing a trade. Commission-free still leaves room for other charges, such as foreign exchange fees and the lesser-known ECN fees.

ECN Fee? 

ECN stands for Electronic Communication Network. ECNs are intermediaries that match brokers to stock exchanges. ECNs charge on a per-share basis for their services, typically fractions of a penny. Some brokers pass these fees down to their clients, others just absorb them.

When Do They Apply?

ECN fees only apply to trades that "removes liquidity". A trade that removes liquidity are those that fill immediately. Such as market orders or a marketable limit orders

A trade that adds liquidity is one that wouldn't fill right away, such as a limit sell order above the current ask price or limit buy order below the current bid price.

For example, if SPY has an ask price of $250 

- A market order or limit buy order of $250 would be filled immediately, taking it off of the exchange's order book, thus removing liquidity

- A limit buy order of $245 would not be filled immediately, sitting on the exchange's order book until a willing seller arrives, thus adding liquidity.

But Wait, There's More

Orders in blocks of 100 shares are considered broad lots. A block of 100 shares is the standard trading unit for exchanges and this standardization can increase liquidity. Orders less than 100 shares are known as odd lots, these can remove liquidity. If you put in an order for 105 shares, this is known as a mixed lot. These get split into two orders, one broad (100) and one odd (5). Only the odd portion will remove liquidity.

So even if you put in a non-marketable limit order, you could still be removing liquidity by having odd lots.

Should I Avoid Them?

ECN fees are annoying, especially when you don't expect them. However, it's simply not worth the trouble trying to avoid them. By using orders that add liquidity, you face the bigger cost of not having your order filled. It's also not practical to trade only in broad lots. If you really want to avoid ECN fees, try finding a broker that doesn't pass them down to you. If such a broker doesn't exist, or exists but has other pitfalls, remember the fee is small. Think long term, ECN fees won't matter in the big picture.















Comments

Popular posts from this blog

Today's Special: Humble Pie

You champion a project, fight for an idea, and then...reality sets in. That churning in your stomach isn't butterflies, it's the realization you've missed the mark.  Pride will puff up your chest, and kick in the "defend at all costs" instinct. But arguing with the umpire never changed a call. Admitting you're wrong isn't a sign of weakness. It can strengthen your professional standing. In a world obsessed with the illusion of infallibility, the courage to adjust course is a breath of fresh air. It shows you're confident enough to be wrong, and adaptable enough to learn from it. Do your research, think critically, and stand behind your decisions. But when the data whispers (or screams) otherwise, don't be afraid to swallow that slice of humble pie. Be the first to acknowledge. Don't wait for someone to point out your mistake. Be open, take responsibility, and most importantly, focus on what you're going to do to address it. Don't dwell ...

When Perfect Becomes a Problem: The iCar Story

Let's talk about Apple's iCar, or rather, the ghost of it. A decade. Ten billion dollars. Poof. Gone. Like a puff of smoke from a dream that never quite woke up. They wanted to launch a revolution, a fully-formed, flawless chariot. But revolutions aren't born in secret labs; they're forged in the messy, chaotic crucible of the real world. You don't build a movement by hiding in the shadows. You don't create a product people love by ignoring them. You don't change the world by waiting for perfection. It's about the minimum viable. It's about shipping early, shipping often, and listening—really listening—to the people you're trying to serve. Apple built a cathedral of secrecy. A monument to what might have been. And then, they tore it down.  They spent billions on a dream, while ignoring the simple truth: the market doesn't care about your dreams. It cares about solutions. It cares about things that work. So, here's the lesson: stop chasing...

Why We Shouldn't Be Afraid of Ambiguity

Ambiguity. That fuzzy monster that chases us down darkened hallways, whispering doubts about our roadmap and feature sets. You know the feeling. You constantly wrestle with unknowns: Will users like this? Is this the right direction? Frankly, if you had a nickel for every time the answer wasn't crystal clear, well, you might actually want to chase that ambiguity down the hall. But here's the thing: ambiguity isn't your enemy. It's your dance partner. Innovation rarely happens in a land of perfect clarity. Sure, there's a time for well-defined processes. But when you're creating something new, there are bound to be more questions than answers. The key is to learn to waltz with the unknown .  Embrace the experiment. Don't be afraid to throw some spaghetti at the wall and see what sticks.  Focus on outcomes, not outputs. Don't get hung up on features. What problem are you trying to solve? How will you measure success? Get comfortable with "go...