Move stop loss (to break even)

[darkknight9394]

Hi gents,

I am wondering if there's anyway to do the following. After we are in a trade for 3 days, if we are profitable, we move the stop loss to break-even point (at the fill price). I have include 2 segments below. The first one sells 1/3 of the shares, whereas in the 2nd statement we want to move the stop loss to fill price. I am encountering an error which leads me to think there's no way of modifying the stop loss once it's been set.

ERROR ==> ValueError: Either buy_shares or sell_shares must be set when a stop is set.

` if ctx.long_pos().bars == N_BAR_SHORT_TERM and ctx.long_pos().pnl > 0:
ctx.sell_shares = ctx.long_pos().shares/3
if is_verbose:
print(f"{current_date} - SELL HALF for {symbol}: held for {N_BAR_SHORT_TERM} bars. shares {ctx.sell_shares}")
return

    # this simulates move stop loss to breakeven
    if ctx.long_pos().bars == N_BAR_SHORT_TERM+1 and ctx.long_pos().pnl > 0:
       print("Shares remaining", ctx.long_pos().shares)
       ctx.cancel_stops(ctx.symbol)
       # ideally I will have a new stop loss order set here for breakeven, or order amend 
       return

`

Temporary solution that I come up with is to first cancel the order, afterwards make use of the ctx.session dictionary to continuously monitor where the close price falls below a breakeven, if so sell the remaining shares at the breakeven point. I am fully aware this is not a clean approach and the code can be very spaghetti once more profit taking rules are added. Is there anyway we can do that in a more clean fashion?

' #################################################################################################################
# The logic is as follows:
# 1) after N_BAR_SHORT_TERM if we are profitable, sell 1/3 of the shares
# 2) on the same day we move the stop loss to breakeven by
# i) cancel the existing stop loss
# ii) setup session dict for the symbol to monitor the breakeven price and decision
# iii) continuous monitoring if the price is below the breakeven price if so sell it

    if ctx.long_pos().bars == N_BAR_SHORT_TERM and ctx.long_pos().pnl > 0:
        ctx.sell_shares = ctx.long_pos().shares/3
        if is_verbose:
            print(f"{current_date} - SELL HALF for {symbol}: held for {N_BAR_SHORT_TERM} bars. shares {ctx.sell_shares}")
        return

    # i) cancel the existing stop loss
    if ctx.long_pos().bars == N_BAR_SHORT_TERM+1 and ctx.long_pos().pnl > 0:
        remaining_shares = ctx.long_pos().shares
        #if ctx.long_pos().bars == N_BAR_SHORT_TERM and ctx.long_pos().pnl > 0:
        print("Shares remaining", remaining_shares)
        ctx.cancel_stops(ctx.symbol)

        #ii) setup session dict for the symbol to monitor the breakeven price and decision
        if ctx.session.get(symbol, True):
            # # Clear the signal once trade is entered.
            ctx.session[symbol] = {
                'fill_price': ctx.long_pos().entries[0].price,
                'bar': np.nan,
                'date': None,
                'monitor_breakeven': True,
            }
        return

    #iii) continuous monitoring if the price is below the breakeven price if so sell it 
    # we are selling all remaining shares if the price is below the breakeven
    if ctx.session.get(symbol, False) and ctx.session[symbol]['monitor_breakeven']:
        if ctx.close[-1] <= ctx.session[symbol]['fill_price']:
            ctx.sell_fill_price = ctx.session[symbol]['fill_price']
            ctx.sell_shares = ctx.long_pos().shares
            if is_verbose:
                print(f"{current_date} - BREAK_EVEN POINT for {symbol}: close {current_close:.2f} below breakeven {ctx.session[symbol]['fill_price']:.2f}")

            ctx.session[symbol] =None
        return

'

[edtechre]

Thanks for the info @darkknight9394. I will think about how to support modifying stops that have not yet triggered. Let me know if you have any suggestions on what the API should look like.