Almost always this type of problem is caused by not managing your leverage. The backtester will allow your algo to borrow unlimited amounts of money.

You can monitor context.account.leverage in your algo to track your leverage. Lots of examples here in the forums on how to do so.

Josh is right.

And your PvR hits a high of only around 40% and ends at 7.77%. PvR stands for Profit vs. Risk, it is a measure of returns based on amount put into play, and so it is looking more solely at code merit while ignoring starting capital. You can worry about starting capital later when you have an investor in the picture or want to enter the contest.

Usually a problem like this can be resolved to some degree more in line realistically by inserting a line like this:

    for one_stock in data:  
        if get_open_orders(one_stock): continue  

...however that didn't do the trick here.

So you might also give track_orders() a try, and I'm interested in knowing whether that helps if you would please, if you try it. (My hunch is some unfilled orders).

It is in Daily mode so far. Your schedule lines are specifying minutes 1 and 10. They may not be running when you expected them to. Add this line in both functions and see what you can make of that. It seems to me they both run at minute zero.

    print get_datetime().time().minute  

I tend to almost always track cash these days, besides the obvious it offers a sense of when big buys/sells are happening.

    record(cash = context.portfolio.cash)  

Alright, hope those help. Also here's some code to track PvR:

    schedule_function(pvr, date_rules.every_day(), time_rules.market_close())

def pvr(context, data):  
    c = context  
    if 'risk_hi' in c:  
        shorts = 0  
        for p in c.portfolio.positions:  
            shrs = c.portfolio.positions[p].amount  
            if shrs < 0:  
                shorts += int(abs(shrs * data[p].price))

        cash_dip  = int(max(0, c.portfolio.starting_cash - c.portfolio.cash))  
        risk      = int(max(cash_dip, shorts))  # Amount in play, maximum of shorts or cash used  
        c.risk_hi = max(risk, c.risk_hi)

        if c.risk_hi != 0:     # Avoid zero-divide  
            record(PvR_Ret = (100 * c.portfolio.pnl / c.risk_hi))        # Profit_vs_Risk returns

    else:    # Init this instead in initialize() for better efficiency  
        c.risk_hi = 0  

Thank you for your input, Josh and garyha. I've modified the code to take into account the 3.0 leverage limit. However I'm still not sure if the results are realistic or not, taking into consideration the backtest ends with around -$14 million in cash.

Insert this on line 141 to let those sells settle (I missed this before):

    if get_open_orders(): return  

The result will look awesome (due to extreme negative cash). PvR will be about half the benchmark. Then if you set maximum_leverage to 1.0, the code will beat SPY handily. The line above will result in the loss of shorting, maybe store those calcs and use them in the next frame.