Inside day breakout

Checked October 2026

An inside day sits entirely inside the prior day's high and low. Lien's rule waits for two of them in a row, then buys a break of that range or sells a break the other way. She wrote it up in 2008, and it is a chapter of her currency book. Backtoast ran it. This version, without Lien's scale-out, failed our test, losing 2.6% a year over 53 trades.

Backtoast

You pay $99 for two full tests of your own strategy, and a pass is an offer of 30% of the profit Backtoast makes trading it with its own money.

Inside day breakout

Two inside days in a row mean the range has been shrinking, and the trade bets the break out of it runs. The entry is above the latest inside day's high or below its low, and the stop sits at least 10 pips past the other side. Lien takes half off at a gain equal to the risk, moves the stop to breakeven and trails the rest under the two-day low.

The run couldn't scale out or move to breakeven, so it held the full position and trailed the two-day low from the start, and a stop-out ended the trade without reversing it.

Forex turtle trading buys a 20-day breakout on the same pairs instead of a two-day squeeze.

When it works

Lien points it at trending pairs like euro-dollar, dollar-yen and sterling-dollar, because quiet stretches are followed by bigger moves, and in a trending pair the break is more likely to run. It loses when the break fails and price falls back into the range, but the narrow range puts the stop close to the entry, so a false break gets cut quickly. It made +0.23% a trade in the last six months of our run, against a loss before that.

Origins

Kathy Lien wrote it up for TradingMarkets in 2008, and it's chapter 12 of her Day Trading and Swing Trading the Currency Market, 3rd edition, 2016. She gave chart examples, not figures. The run traded EUR/USD, GBP/USD and USD/JPY from late 2021 to October 2026.

The run is Backtoast's, from 29 October 2026, after costs.