Hi everyone,

First of all, i'd like to say that Quantopian is looking great and seems a very interesting platform.

I've been playing around with Quantopian. And i've noticed there are some strange discrepancies.

1. I've yet to find a way to access single Transaction details. As I understand it is impossible to get properties on open positions from the same stock. I.e. If I buy Apple once at 100 and then later at 110, there is no way of retrieving the return on each transaction separately, as well as closing the separately. (Yes, I realise for many things it doesn't change much)
   
2. It seems the Cost Basis isn't working properly. If I buy a stock and
   log the cost basis, its not the same as the price paid, even though
   no further stocks have been purchased. I assume i'm doing something
   wrong...

cost_basis
Float: The volume-weighted average price paid (price and commission) per share in this position.

Output:
2014-05-05startportfolio:84INFOSetting up basic portfolio...
2014-05-05startportfolio:91INFOBuying ADBE : [email protected]**61.43** : 491.44
2014-05-05handle_data:52INFOCost Basis: ADBE : 0.0
2014-05-06handle_data:52INFOCost Basis: ADBE : 59.48

1. Returns method
   When using the returns method I keep getting an error. While any other method for data[sid] does seem to work in my code.
   ---error----
   There was a runtime error.
   RuntimeInvalidTransform: 0064 You accessed data in some way other than data[sid].returns. We do not support calling returns in other ways.

Code:

def handle_data(context, data):  
    # Implement your algorithm logic here.

    # data[sid(X)] holds the trade event data for that stocks.  
    # context.portfolio holds the current portfolio state.  
    #General Vars  
    cash = context.portfolio.cash  
    #margin = int(cash/10)  
    #free_cash = int(cash - margin)  
    free_cash = cash  
    handle_data.target = int(free_cash * context.weight)  
    #log.info("Current Cash: %s" % (cash))  
    #log.info("Margin: %s" % (margin))  
    #log.info("Free Cash: %s" % (free_cash))  
    if context.portfolio.positions_value <= 0:  
        startportfolio(context, data)  

    #for stock in context.stocks:  
    returns = data[114].returns  
    log.info('Return %s' % (returns))

def startportfolio(context, data):  
    log.info("Setting up basic portfolio...")  
    for stock in context.stocks:  
        p_current_price = float(data[stock].price)  
        p_amount_order = int(0.5 * handle_data.target / p_current_price)  
        p_costs = p_amount_order * p_current_price  
        order(stock, +p_amount_order)  
        log.info('Buying %s' % (stock.symbol) + " - " + str(p_amount_order) + "@" + str(p_current_price) + " - %s" %p_costs )