Question: How to decide buy and sell order for once?

[Reo Inoue]

Dear all
I make the strategy to use RSI. I make easy example code to make sure the behavior follows.

if self.RSI[0] < -80, I buy.
if self.dataclose[0] > -20, I sell.
And I check the command prompt, there are many sell order.
2014-02-24, SELL CREATE, 14837.68
2014-02-25, SELL EXECUTED, Price: 15002.51, Cost: 14803.64, Comm 0.00
2014-03-06, SELL CREATE, 15134.75
2014-03-07, SELL EXECUTED, Price: 15280.76, Cost: 14933.76, Comm 0.00
....

I want to do buy and next time should be sell. How to do these?

[ab_trader]

@Reo-Inoue

def next(self):

    if not self.position: # check if open position exists

        if self.RSI[0] < -80, I buy # open position

    if self.position:

         if self.dataclose[0] > -20, I sell # close position

[backtrader]

Most assets have prices well above 0 and hence

if self.data.close > -20

will probably always evaluate to True (the asset in use here could have prices below 0 of course) and therefore it will sell

Additionally, the RSI oscillates between 0 and 100, so this

if self.rsi < -80

is for sure never going to evaluate to True, i.e.: it will never buy

If there is also no control of whether one is in the market, sell orders will be continuously issued.

The code by ab_trader respects the original but controls the position but controls the position. The final outcome will probably be:

• One sell
• No buy ever