Skyscraper is a free MT5 chart-window trend indicator from TrendLaboratory: a stop-and-reverse trailing line that flips between acting as a support level in an uptrend and a resistance level in a downtrend, with Buy/Sell arrows marking the exact bar each flip happens. It’s an instant download, and its ratcheting trailing-stop logic makes it a straightforward line to build simple trend-following rules around.

How the Trailing Line Is Actually Built

Instead of calling MT5’s built-in ATR, Skyscraper computes its own volatility measure directly: for each bar it sums High - Low across the last Length bars (default 10) and divides by Length, giving a simple average range rather than a Wilder-smoothed ATR. It then tracks the running maximum and minimum of that average range and combines them into a Step value, scaled by the Kv input (default 0.9) and converted into points.

Depending on the HighLow input, it builds a candidate support/resistance level either from the bar’s Low/High (MODE_HighLow, the default) or from its Close (MODE_Close), offset by twice the Step. A trend flip is triggered only when the close breaks through the previous bar’s opposite-side level. Once trending up, the support line can only ratchet upward — it takes the higher of the new candidate level and the previous bar’s level — and is plotted as the “Lower Skyscraper” line. Once trending down, the resistance line can only ratchet downward and is plotted as the “Upper Skyscraper” line. A third value — the “Skyscraper Middle” line — sits one Step away from the active trailing line, further offset by the Percentage input, giving a secondary marker between the trailing line and price.

Buy and Sell arrows are placed exactly on the bar where the active line switches sides: a Buy arrow appears the moment the trailing line flips from resistance to support (trend turns up), and a Sell arrow appears the moment it flips from support to resistance (trend turns down).

How to Read It on Your Chart

• Lower Skyscraper (LimeGreen) present — the market is currently classified as trending up, and this line is the ratcheting support level.
• Upper Skyscraper (DeepPink) present — the market is currently classified as trending down, and this line is the ratcheting resistance level.
• Arrows — mark the specific bar of each trend flip; because the underlying line only ratchets in one direction per trend, a close back through it is what triggers the next flip and arrow.
• Skyscraper Middle — an auxiliary marker offset from the main line by the Step value and the Percentage input, useful as a secondary visual reference between the trailing line and current price.

Input Parameters (Actual Defaults From the Code)

• Length = 10 — the lookback used for the indicator’s own average High-Low range calculation (not a true Wilder ATR).
• Kv = 0.9 — a multiplier applied to the combined max/min average range when computing the Step offset; higher values widen the trailing line’s distance from price and reduce flip frequency.
• Percentage = 0 — shifts the Skyscraper Middle marker toward or away from the extreme lines, as a percentage of the Step value.
• HighLow = MODE_HighLow — selects whether the support/resistance candidate levels are built from each bar’s High/Low or from its Close (MODE_Close).

Where This Fits in a Trading Plan

Skyscraper’s stop-and-reverse design makes it a natural fit for a mechanical, always-in-the-market approach: every bar the market is classified as either up or down, with no neutral state, so it suits traders who want a clear, binary trend read rather than a nuanced strength gauge. The ratcheting support/resistance line also doubles as a candidate trailing-stop level for an open position, since by construction it never moves against the current trend once set. The separate Skyscraper Middle line, adjustable via Percentage, gives some flexibility to place that reference closer to price for tighter trade management or further away for a looser trail.

Honest Limitations

Because the volatility measure is a simple average range rather than a true ATR (it does not account for gaps against the previous close), the Step value can understate volatility around gapping opens compared to a Wilder ATR-based system. The stop-and-reverse design also means it is always in a trend, up or down — there’s no neutral or “no trend” state, so during genuine ranging conditions it will still flip back and forth and generate arrows on both sides with no separate chop filter. As with any single-line trend-following system, it works best combined with an independent trend-strength or volatility filter rather than traded purely on its own arrows.