Build a Multi‑Symbol Scanner in Pine v6: request.security(), Tables, and Limits

• Each request.security() call is a performance hit; too many calls will slow or fail scripts.
• There’s a limit to simultaneous requested series. Keep lists small and focused.
• Pine scripts run on the chart symbol; scanners are best for watchlists, not whole exchanges.

//@version=6
indicator("Mini Scanner", overlay=false)

// Define a small watchlist (5-20 symbols). Too many will hit limits.
syms = array.from("AAPL", "MSFT", "NVDA", "TSLA", "AMZN")

len = array.size(syms)

// Results arrays
var arrClose = array.new_float()
var arrUp = array.new_bool()

if barstate.isfirst
    array.resize(arrClose, len)
    array.resize(arrUp, len)

for i = 0 to len - 1
    string s = array.get(syms, i)
    float c = request.security(s, timeframe.period, close)
    bool up = c > request.security(s, timeframe.period, ta.ema(close, 50))
    array.set(arrClose, i, c)
    array.set(arrUp, i, up)

// Table output
var table t = table.new(position.top_right, 3, len + 1, border_width=1)
if barstate.isfirst
    table.cell(t, 0, 0, "Symbol", text_color=color.white, bgcolor=color.new(color.gray, 0))
    table.cell(t, 1, 0, "Close")
    table.cell(t, 2, 0, "Above 50EMA")

for i = 0 to len - 1
    string s = array.get(syms, i)
    float c = array.get(arrClose, i)
    bool up = array.get(arrUp, i)
    table.cell(t, 0, i + 1, s)
    table.cell(t, 1, i + 1, str.tostring(c, format.mintick))
    table.cell(t, 2, i + 1, up ? "Yes" : "No", text_color=up ? color.lime : color.red)

• Replace the EMA condition with your own signal (e.g., Donchian breakout, RSI cross).
• Add color coding by regime, or sort top rows with simple rank heuristics (beware complexity limits).
• Use inputs to toggle watchlist presets (tech, energy, futures) without modifying code.

• Keep the symbol list tight. 5–20 is a practical range.
• Reuse calculations and avoid nested request.security() in deep loops.
• Limit plots; render via tables for compact UI.
• Test on smaller history first; expand once stable.