Lowest

Syntax

Lowest[N](price)

Parameters

Formula

Lowest[N](price) = min( price[0], price[1], ..., price[N-1] )

where price[0] is the current bar and price[N-1] the oldest bar in the window.

How it works

On each bar, ProBuilder scans a sliding window of the last N values of the given series and returns the minimum. The window always includes the bar currently being evaluated, which matters for breakout logic: on the bar where price makes a new low, Lowest[N](low) equals that new low, so low < Lowest[N](low) can never be true. Shifting the whole expression back one bar with Lowest[N](low)[1] yields the prior N-bar low, the value breakout systems actually compare against.

The function accepts any series, not just raw prices. Lowest[20](RSI[14](close)) returns the lowest RSI reading of the last 20 bars, a pattern used for normalisation, and Lowest[N](low) together with Highest[N](high) forms the Donchian channel and the denominator of the Stochastic oscillator.

Lowest answers "what is the minimum"; the companion LowestBars answers "how many bars ago did it occur".

Examples

Example 1, Adaptive lower band (Indicator)

// Use the current low when it undercuts the 30-bar lowest close
IF Low < Lowest[30](close) THEN
  bandL = Low
ELSE
  bandL = Lowest[30](close)
ENDIF
RETURN bandL

Builds a lower band from the smaller of the current low and the lowest close of the last 30 bars, so intrabar spikes below the closing-price floor are captured immediately.

Example 2, Donchian exit stop (ProOrder)

// Enter on a 20-bar breakout, exit at the 10-bar low
IF NOT OnMarket AND close CROSSES OVER Highest[20](high)[1] THEN
  BUY 1 CONTRACT AT MARKET
ENDIF

IF LongOnMarket THEN
  SELL AT Lowest[10](low) STOP
ENDIF

Places a stop order at the lowest low of the last 10 bars, a classic trailing exit that follows the market up as new higher lows are set.

Example 3, Near the 52-week low (ProScreener)

// Daily scan for instruments within 2 percent of their one-year low
low52    = Lowest[252](low)
distance = 100 * (close - low52) / low52
SCREENER[distance < 2](distance AS "Pct above 52w low")

Returns instruments whose close sits less than 2 percent above the lowest low of the last 252 daily bars, roughly one trading year.

Interpretation

The rolling minimum is the most direct definition of support: the price level that held over the chosen window. Price approaching Lowest[N](low) is testing that support, and a close below it is a range breakdown. Trend followers read a break of the N-bar low as a short entry or a long exit, while mean-reversion traders read the distance between price and the rolling low as available downside room.

Window length sets the character. Lowest[10] tracks swing lows for tight trailing stops, Lowest[252] tracks the one-year floor used in relative strength scans.

Common errors and gotchas

• The window includes the current bar. low < Lowest[N](low) is always false. For breakdown detection, compare against the previous window: close CROSSES UNDER Lowest[N](low)[1].
• N beyond loaded history. When fewer than N bars are available, the result is computed on whatever exists, so early backtest values differ from chart values. Load enough history, or in automated systems raise DEFPARAM PreloadBars.
• Lowest is not MIN. MIN(a, b) compares two expressions on the same bar; Lowest[N](a) scans one series through time. MIN cannot take a period and Lowest cannot take two series.
• Value versus location. Lowest gives the level, not the timing. To know how many bars ago the minimum printed, use LowestBars, for example to measure how stale a support level is.

Related instructions

• Highest, the symmetric rolling maximum.
• LowestBars, number of bars since the minimum occurred.
• HighestBars, number of bars since the maximum occurred.
• MIN, minimum of two expressions on the same bar.
• DonchianChannelDown, packaged channel line built on the rolling low.
• Stochastic, oscillator normalised by the highest-lowest range.
• Average, moving average, the smoothing counterpart.
• Range, current bar's high minus low.