Engine · How

PCL: Profit Closes Loss.

PCL is the Hydra Vision engine that decides how a grid closes. It uses the profit of one position to remove the loss of another, so a grid can get smaller while it is still running.

Why it was built

In a traditional grid, the single average price of all open positions is both the only exit and the only way to reduce risk. Every position waits for the market to come back to that one price. PCL was built because that arrangement ties two separate jobs together: taking profit and reducing risk. Hydra Vision's first engine was designed to pull them apart.

How it works

A grid starts with its first position, the anchor. The outermost position is called the Frontier. As the price moves, some positions sit in profit and others in loss.

PCL pairs a position in profit with a position in loss. It calculates their combined average price, including the costs they have built up (commission and swap) and a small profit target. When the market reaches that price, both positions close together. The result is a small booked profit, one loss taken off the books, and a grid with fewer open positions. Hydra Vision calls the shrinking of the grid grid compaction.

To decide which positions to pair, PCL splits every grid in two at its volume-weighted average price: a profit side and a loss side. As positions open and close, that dividing line moves, so there are normally positions on both sides for PCL to work with.

Because risk is reduced along the way, the grid does not depend on one averaged exit to bring its risk down. That separation is what lets steps be more dynamic and means volume does not have to grow aggressively to bring the exit closer.

Two engines

• Dynamic PCL closes pairs, as described above. Depending on the strategy, it targets the anchor, the position next to the anchor, or the highest-risk position on the loss side.
• Whole PCL is classic grid averaging: every open position closes together at one average price, including costs and a profit target. Some strategies use it on purpose, and it is there as a fallback.

PCL strategies

Which positions PCL targets, and what happens to the positions that remain, is set by the PCL strategy you choose. The main ones are Hunter (keep the grid compact until one non-anchor position is left to trail), Bounce (keep the anchor and close the inner positions as the market extends), Multi Trail (keep a small number of positions trailing at once) and Frontier Retention (close the grid on an average that leaves out the Frontier, which then trails). Each one has its own risk limits, and when a strategy no longer applies, PCL can switch to de-risking the grid.

A worked example

From a GBPUSD backtest on 19 March 2026: the anchor, at −28.84, and level 4, at +36.99, closed together for +8.15, net of costs. The grid went from 6 positions to 4. This was that grid's first partial close.

The settings, at a high level

• PCL strategy and which PCL engines are switched on.
• Profit targeting: the small target each PCL close books, fixed or scaled.
• Strategy thresholds: the position count and volume limits for each strategy.
• De-risking: when PCL stops following the strategy and targets the highest-risk positions instead.
• Feasibility: how far the market may have to retrace for a close to count as reachable.

The PCL strategy and engines are part of the Strategy Print; the targets and thresholds that tune them are part of the Tuning Print.

How PCL works with the other engines

PCL decides how positions close. SmartEntry decides when the next one opens, and was built because PCL's data showed that poor re-entries made PCL work harder. GridSense records every PCL close with its reason, and hands that record to backtest reports, live analytics and back to the engines. You can watch PCL closes happen bar by bar in Replay.

Read the guides

• PCL concepts
• PCL Strategies
• PCL Engines settings
• PCL De-Risking settings
• Risk Management