Strategies and backtesting - GoCharting

A strategy declares itself with strategy(...) instead of indicator(...) and places orders with the strategy.* functions. The orders are simulated: a built-in broker emulator fills them against the chart’s bars on a simulated account. Nothing is sent to a real broker.

GoCharting is a charting and analytics tool. This is not investment advice. Trading and investing carry a high risk of loss and are not suitable for everyone. You can lose some or all of your money.

//@lipi=2
strategy("Average cross", overlay=true, initial_capital=10000, default_qty_value=2, commission_value=0.1)
fast = talib.sma(close, 10)
slow = talib.sma(close, 30)
if talib.crossover(fast, slow) {
    strategy.entry("Long", strategy.long)
}
if talib.crossunder(fast, slow) {
    strategy.close("Long")
}
plot(fast, title="Fast")
plot(slow, title="Slow")

The script runs once per bar; order calls may sit in if, loops and functions. See Orders and positions for fills and Reading a strategy’s results for the account variables. In an indicator() script the order calls and strategy.* variables compile but do nothing.

The declaration

strategy(title, ...) is called once at the top level; only title is required and every argument is const. The display arguments (shorttitle, overlay, format, precision, scale, max_*_count, behind_chart) are those of indicator(). The account arguments:

Argument	Default	Meaning
`initial_capital`	1000000	Starting equity.
`default_qty_type`	`strategy.fixed`	`default_qty_value` as units (`strategy.fixed`), or as money (`"cash"`) or percent of equity (`"percent_of_equity"`) divided by a price. `strategy.cash` does not exist; the strings compile, but the price is the order’s `limit` or `stop`, so an order with neither and no `qty` stops the script: `Invalid order quantity`. Use `strategy.fixed`, or pass `qty`.
`default_qty_value`	1	Size of an order with no `qty`.
`commission_type`	`strategy.commission_percent`	Or `strategy.commission_cash_per_order`, `strategy.commission_cash_per_contract`.
`commission_value`	0	Charged when a trade opens and when it closes; as a percent, 0.1 is 0.1%.
`pyramiding`	1	Open entries allowed in one direction.
`process_orders_on_close`	false	Also fill orders at the close of the bar that placed them.
`calc_on_order_fills`	false	Run the script again within the bar after an order fills.
`calc_on_every_tick`	false	On a forming realtime bar, run on every tick, not at the close.

These values are not checked (pyramiding=0 compiles). There is no slippage, margin or currency argument.