My stop-loss order is getting executed when it shouldn't

leecallen

Hi. This is a big program, I have been using it for a long time, but yesterday I discovered a problem and it's driving me crazy.

I am back-testing using Forex 5M data.

I open a BUY market order on 7/24 at 14:00.
The order Completes (opening the order) in the next bar at 14:05 at price 1.11351.
I open a stop-loss order below my executed BUY price:

self.sell( exectype=bt.Order.Stop,  price=1.11194, size=self.order_size )

and a take-profit order above my executed price:

self.sell( exectype=bt.Order.Limit, price=1.11520, size=self.order_size )

Many bars go by that don't have lows below my SL or highs above my TP.

Then the next morning at 7:40 I get this bar:

Date           Time               Open   High    Low     Close   Volume
25.04.2019 07:40:00.000 GMT-0400,1.11243,1.11260,1.11235,1.11259,1505.38

the low is still above my SL and the high is still below my TP, but both my SL and TP orders complete!

My next() method is printing each bar so I know that's the one.

Here's a dump of my SL order -- print(order) in the notify_order for status Completed:

2019-07-25T07:40:00-04:00, 1.11416 1.11433 1.11394 1.11396 33.958517326947884 1.0 2
Ref: 41
OrdType: 1
OrdType: Sell
Status: 4
Status: Completed
Size: -100
Price: 1.1119400000000002
Price Limit: None
TrailAmount: None
TrailPercent: None
ExecType: 3
ExecType: Stop
CommInfo: <backtrader.comminfo.CommInfoBase object at 0x7fde4c3ad780>
End of Session: 737264.9999999999
Info: AutoOrderedDict([('type', 'sl'), ('parent', 40)])
Broker: None
Alive: False
2019-07-25T07:40:00-04:00, order #41 SELL completed, info AutoOrderedDict([('type', 'sl'), ('parent', 40)]) price 1.11194 size 100.00 pnl -0.16 pprice 0.00000 balance    999

Why did that SL order fire?

I'm running Backtrader 1.9.74.123

Any ideas would be hugely appreciated.

leecallen

@leecallen Never mind -- I figured it out.

The next bar at 7:45 hits both the SL and the TP. And then I remembered: in Backtrader the order events get processed before the next() logic. And some bug in my code (I know where it is) is posting the prev-bar datetime in my logging.

And I guess I need to set up OCO or bracket orders or something so my SL and TP can't both fire.

benmercerdev

"And some bug in my code (I know where it is) is posting the prev-bar datetime in my logging."

In some ways these types of bugs are the worst and the best. They're good because it means you were probably right about the logic. They're horrible because you spend hours trying to find them.

Good luck!

SPECULARI FUND

May be you can help how check type of order that accepted? Because I am updating take profit Limit order by moving average price and every updating of price I receiving new Limit order - previous not replaced.