Waited till weekend and with 1.80.6 it's really confusing because Spread=marketVal() now contains a price and it seems to be priceClose(-1) that means peeking one tick into future:
[1: Mon 18-03-05 00:01:00] (1.23173)
2018-03-05 00:01:0.039, EUR/USD: 1.23174, Spread: 1.23173
2018-03-05 00:01:2.644, EUR/USD: 1.23173, Spread: 1.23172
2018-03-05 00:01:2.655, EUR/USD: 1.23172, Spread: 1.23171
2018-03-05 00:01:2.688, EUR/USD: 1.23171, Spread: 1.23170
2018-03-05 00:01:2.718, EUR/USD: 1.23170, Spread: 1.23171
2018-03-05 00:01:4.305, EUR/USD: 1.23171, Spread: 1.23170
2018-03-05 00:01:6.248, EUR/USD: 1.23170, Spread: 1.23171
2018-03-05 00:01:6.771, EUR/USD: 1.23171, Spread: 1.23172
