How Trades Are Actually Routed, Split, and Filled

This lesson teaches you how trades are actually routed, split, and filled.

Part 1: The Big Truth About Swaps

Beginner Belief

“I swap Token A → Token B directly.”

Reality

Your trade is often split, routed, and optimized across multiple paths.

Key Insight

Part 2: What Is Routing?

Routing means finding the best path for your trade.

Example

You want:

ETH → USDT

Possible Routes

• Direct route:

  ETH → USDT

  
  

• Multi-hop route:

  ETH → USDC → USDT

  
  

Why Multi-Hop Routes Exist

Sometimes indirect routes provide better pricing.

Who Decides the Route?

Routers used by protocols such as:

• Uniswap

• 1inch

  
  

Key Insight

Part 3: Trade Splitting

What Is Trade Splitting?

Trade splitting breaks one trade into multiple smaller trades.

Example

You swap:

$10,000 ETH → USDC

Instead of using one pool, the trade may be split like this:

• $4,000 via Pool A

• $3,000 via Pool B

• $3,000 via Pool C

  
  

Why Trades Are Split

• Reduce slippage

• Improve pricing

  
  

Key Insight

Part 4: Slippage

What Is Slippage?

Slippage is the difference between the expected price and the actual execution price.

Why Slippage Happens

• Low liquidity

• Large trade size

• Fast price movement

  
  

Example

• Expected: $1,000

• Received: $970

  
  

Slippage = $30 loss

Key Insight

Part 5: Slippage vs. Trade Size

The Relationship

Slippage ∝ Trade Size / Liquidity

Meaning

• Bigger trade → more slippage

• Bigger liquidity → less slippage

  
  

Operator Rule

Always check pool depth before trading.

Part 6: Gas vs. Slippage Tradeoff

Here is where execution becomes more complex.

The Tradeoff

Routing and splitting may improve pricing, but additional steps increase gas costs.

• Lower slippage → higher gas

• Lower gas → worse execution price

  
  

Key Insight

Part 7: Speed and Execution Timing

What Affects Execution Speed?

• Network congestion

• Gas fee priority

  
  

Risks of Slow Execution

• Price changes before confirmation

• Failed transactions

  
  

Example

You submit a trade, wait for confirmation, and the market moves before execution.

Result: You receive a worse price.

Operator Rule

In volatile markets, execution speed often matters more than gas savings.

Part 8: DEX Aggregators

What Are Aggregators?

Aggregators scan multiple DEXs to find the best execution route.

Examples

• 1inch

• ParaSwap

  
  

What They Do

• Find optimal routes

• Split trades

• Optimize execution

  
  

Important Tradeoff

More optimization usually means:

• Higher routing complexity

• Higher gas usage

  
  

Key Insight

Part 9: Hidden Execution Risks

1. MEV (Miner Extractable Value)

What Happens

Bots detect your transaction and attempt to:

• Front-run you

• Sandwich your trade

  
  

Result

• Worse pricing

• Higher slippage

  
  

2. Failed Transactions

Sometimes you pay gas fees even when the trade fails to execute.

3. Misunderstanding Price Impact

Many users ignore how much their trade moves the market itself.

Part 10: Operator Execution Checklist

Before every trade:

1. Check liquidity depth

2. Estimate slippage

3. Compare routing paths

4. Evaluate gas cost

5. Consider market speed and volatility

   
   

Golden Rule

Putting It All Together

A trade is not simply:

Click → Swap

A real DeFi trade is:

• Routed

• Split

• Dynamically priced

• Affected by gas fees

• Affected by execution timing

  
  

Practice Mission

Go to a DEX or aggregator and test the following:

• Small trade vs. large trade

• Compare slippage levels

• Compare routing paths

  
  

Challenge

Simulate this scenario:

“What happens if I double my trade size?”

Observe:

• Price impact

• Slippage increase

• Route changes

• Gas differences

  
  

Final Thought