A first comment. You should be using the newer 'Fundamentals' instead of 'Morningstar' to get fundamental data. Take a look at this post. https://www.quantopian.com/posts/faster-fundamental-data

The answer to the question however is that '.latest' is an attribute and not a method so it can't be called. That's what's causing the error "TypeError: 'Latest' object is not callable". Just omit the parenthesis and it should work.

operating_gains_losses  = Fundamentals.cash_flow_from_continuing_operating_activities.latest

The one constraint with this is that a mask isn't available. If you want to add a mask then one can use the built in factor 'Latest' and then pass it the dataset you want to use.

operating_gains_losses = Latest(inputs=[Fundamentals.cash_flow_from_continuing_operating_activities], mask =universe)

Make sure you import 'Latest' before using it. Also remember to import 'Fundamentals'. Check out the documentation (https://www.quantopian.com/help) for info.

Good luck.

Thanks for your helpful answer, Dan! I just want to add one comment that there usually isn't any sort of benefit to masking a latest pipeline term. All that will do is have the term return NaNs where the mask is false. The mask doesn't get applied until after the data was retrieved, so it won't help to speed things up, either. Depending on what else you're doing in your pipeline, it's usually better to supply the filter as a screen to your entire pipeline, or as a mask to a computation that uses the data later on.

I hope this helps.

The fundamentals are different by the way:

a = operating_gains_losses
b = cash_flow_from_continuing_operating_activities

2018-03-05 05:45 log_pipe:81 INFO  
                  min            mean             max  
    a    -684000000.00    -131600000.00    17000000.00  
    b    -19845000.00    3630431000.00    7671000000.00  

There's more information if you run this.

.

@Jamie I'm having trouble nailing the right way to handle the mask and screen.

This returns 5 securities

def make_pipeline():  
    m = QTradableStocksUS()      # mask  
    m = AverageDollarVolume(window_length=11).top(5, mask=m)

    ...

    pipe = Pipeline(  
        screen  = m,  

This returns only 2. It is the route I thought you were referring to but I must have misunderstood.

def make_pipeline():  
    m = QTradableStocksUS()      # mask

    ...

    pipe = Pipeline(  
        screen  = m & AverageDollarVolume(window_length=11).top(5),