Introducing Indicator Studio: Code Your Own Indicators, Backtests and Scans in One Live Workspace

From preset indicators to your own

Every charting site hands you the same presets: RSI(14), MACD(12,26,9), Bollinger(20,2). They're useful — we ship dedicated pages for all of them. But presets end exactly where your own questions begin. What if you want RSI smoothed over 6 bars instead of 14? A volume surge defined against a 20-bar average rather than a fixed number? An entry rule that combines a momentum flip with a trend filter you invented?

Until now, crossing that line meant graduating to a full programming stack — download data, learn a scripting language, wire up a charting library, debug for an afternoon before you see a single line on a chart. Most people never cross it. The idea stays a wish.

The Studio is our answer: a workspace where writing an indicator feels like writing a spreadsheet formula, and the chart answers while you're still typing. This article is a tour of what it does, with real sessions on real market data — including a backtest that honestly loses to buy & hold, because a tool that only shows flattering numbers is a marketing device, not a research one.

🧭 The workspace

Three panels, no menus to hunt through. On the left, the indicator library — every built-in preset is one click away from being loaded into the editor as editable code. In the middle, the editor itself. On the right, the live preview: candles, volume, and whatever your formula draws, re-evaluated 350 ms after you stop typing. The status bar under the editor tells you, in plain text, whether the engine accepted your formula (ok · 3 lines · 300 bars) or exactly why it didn't.

A formula language you can learn in five minutes

The whole language is name, colon, expression, semicolon. Prices arrive as arrays — C close, O open, H high, L low, V volume — and 45 built-in functions (MA, EMA, RSI, CROSS, HHV, REF…) transform them into lines. The shot above renders this exact formula:

LC:=REF(C,1);                                                    ← intermediate variable
RSI1:SMA(MAX(C-LC,0),6,1)/SMA(ABS(C-LC),6,1)*100,color=#f0b90b;   ← output line, with color
RSI2:SMA(MAX(C-LC,0),12,1)/SMA(ABS(C-LC),12,1)*100,color=#e056fd;
RSI3:SMA(MAX(C-LC,0),24,1)/SMA(ABS(C-LC),24,1)*100,color=#54a0ff;

Three rules carry most of the weight: := defines a private variable, : defines a plotted output line, and color= styles it. Histograms (colorstick), dashed lines (dash) and boolean logic with AND/OR round it out. And the built-in indicators aren't black boxes — they're callable functions, so KDJ(9,3,3), MACD_DIF(12,26) or BOLL_UPPER(20,2) can appear inside your own formulas like any other function.

Because outputs are just declared, iterating is cheap: change the 6 to a 10, and a third of a second later the yellow line re-draws with the new smoothing. That tight loop — type, see, adjust — is the entire point of the Studio.

⌨️ An editor that teaches you the language

You don't have to memorize the function list. The editor is a real code-editing engine with multi-color syntax highlighting, and its autocomplete knows every function, variable and price array in scope — each completion carries its signature and a one-line description, so the doc you need is in the popup, not on another page. Hover any function for the same; hit Ctrl/⌘+Enter to run immediately instead of waiting for the debounce.

Backtest mode: from idea to evidence

Switch to the Backtest tab and the same editor becomes a strategy lab. Two magic names — ENTRY and EXIT — turn output lines into trade signals:

MA5:MA(C,5);                    ← plotted on the chart
MA20:MA(C,20);
ENTRY:CROSS(MA5,MA20);          ← long when fast MA crosses above slow
EXIT:CROSS(MA20,MA5);           ← flat when it crosses back

The simulation is honest by construction: fees and slippage in basis points, optional stop-loss and take-profit, long-only position accounting, and every trade marked on the chart. Below it, an equity curve plots your strategy against buy & hold for the same window.

Tweak anything — capital, fees, a 5% stop, a different pair or interval — and the whole simulation re-runs live, exactly like the indicator preview does.

🔭 Scanner mode: does it generalize?

One good backtest on one symbol proves little — that's how curve-fitted strategies are born. The Scanner mode runs the same ENTRY/EXIT strategy across an entire universe, splitting each symbol's history into an in-sample fit window and a held-out out-of-sample window (60/40, 70/30 or 80/20 — no lookahead, the out-of-sample segment is never visible while the strategy behaves the same everywhere). If an edge only exists in-sample, the table says so.

Four universes ship today: crypto majors, crypto top-20, US stocks & ETFs, and indices/FX/commodities. For parameterized strategies, the site's dedicated Multi-Coin Scanner adds a sensitivity sweep that re-runs the scan across parameter neighborhoods — the same anti-curve-fitting philosophy, one step further.

One engine, every asset class

Crypto is the home turf — pairs load with multi-source failover and aggressive client-side caching — but the Studio deliberately doesn't stop there. US stocks and ETFs (with a dividend-adjustment switch for total-return vs. quoted prices), global indices, forex pairs and commodities all flow into the same engine. Your skill compounds: the RSI formula you wrote for BTC this morning runs unchanged on gold or the S&P this afternoon. The symbol search even resolves tickers beyond the curated list, so the long tail is one query away.

Under the hood it's one WASM indicator engine — the same module that powers the Indicator Lab, the Strategy Backtester and the Multi-Coin Scanner. The Studio is simply the place where you hold the pen directly.

Yours, not uploaded

• →Local-first. Every formula, backtest and scan computes in your browser. Nothing you write leaves your machine, and there is no account to create.
• →Sessions restore. One formula per mode, plus your symbol and interval, persist locally — reload and you're exactly where you left off.
• →My indicators. Save formulas to a personal library in the sidebar, then export the whole thing as a JSON package to share or move between devices — and import one somebody sends you.
• →Fullscreen when you need it. One click expands the workspace to the whole screen; Esc brings you back.