问TradingView (松树脚本)在期货(商品)数据上回测“无数据”？比如银子，金子...？

EN

//@version=4
strategy("SMA", overlay=true, default_qty_type = strategy.percent_of_equity, 
             default_qty_value=99, initial_capital=10000, currency=currency.USD)
strategy.risk.allow_entry_in(strategy.direction.long)

fast = input(defval=15, title="fast", type = input.integer)
slow = input(defval=28, title="slow", type = input.integer)

SMA_fast = sma(close, fast)
SMA_slow = sma(close, slow)

start = timestamp(2020, 1, 30, 0, 0)

p1 = plot(SMA_fast, title="fast", color= SMA_fast>=SMA_slow ? color.orange: SMA_fast<=SMA_slow ? color.black: color.black, linewidth=2)
p2 = plot(SMA_slow, title="slow", color=color.blue, linewidth=2)
fill(p1, p2, color = SMA_fast>=SMA_slow ? color.orange : color.blue, transp = 30)


longCondition = crossover(SMA_fast, SMA_slow)
if (longCondition) and time > start
    strategy.entry("Long", strategy.long)
    alert("BUY (" + tostring(close) + ")", alert.freq_once_per_bar_close)
    
shortCondition = crossunder(SMA_fast, SMA_slow)
if (shortCondition) and time > start
    strategy.entry("Short", strategy.short)
    alert("SELL (" + tostring(close) + ")", alert.freq_once_per_bar_close)