Hello,

I'm using M1 data with BarPeriod = 1440. I assumed that a Spread returned by the marketVal() should be an average spread for a bar, in my case the daily bar. However, the returned spread is a spread for a last M1 tick in a daily bar.

Is it working as designed?

Not as you describe. Only one value is sampled to represent the bar.

Also, different plugins may use different values for MarketVal, not necessarily spread.

You mean that it's working as designed? The returned value shouldn't be the average value but the value of the last tick representing the bar?

I'm using M1 data files from Zorro's site with spread values

The spread is the spread of the close, viz. the last ask-bid quote of the bar.