When you enable “Ladder”, it means that bot will only open the Anchor position (1st one), and bot will wait to open the rest until it hits certain martingale level as specified in MinNoOfMartingalePositions.

This is useful to save yourself from huge drawdown. Please see the scenario below:

Non-Ladder
EURUSD BUY 0.01 at price $1.23456
EURUSD BUY 0.02 at price $1.23446
EURUSD BUY 0.03 at price $1.23436
EURUSD BUY 0.04 at price $1.23426
EURUSD BUY 0.05 at price $1.23416

Ladder, set to MinNoOfMartingalePositions = 4
EURUSD BUY 0.01 at price $1.23456
EURUSD BUY 0.02 at price $1.23416
EURUSD BUY 0.03 at price $1.23416
EURUSD BUY 0.04 at price $1.23416
EURUSD BUY 0.05 at price $1.23416

The ladder scenario above will save you from drawdown because the 4 martingale positions were all opened at price $1.23416 compared to the normal non-ladder mode where each martingale position will be opened at their corresponding price. When current price keeps going down to $1.23416, the non-ladder mode will suffer for more drawdown.

The downside of this setting is if the price never hits the desired martingale level, then you will have a lingering Anchor position.