"Positive delta" refers to a situation where there is an increase or improvement in something. It can indicate that something has grown or become better over time, typically in reference to changes or differences. Full definition
Delta has started rolling out some positive changes to its Main Cabin meals on international routes and, based on positive Delta One customer feedback, it is expanding its partnership with two LA - based chefs to include the airline's LA — Sydney route. (travelingformiles.com)
«We remain cautious on extrapolating the positive delta in EBIT margin achieved in the second half of 2017 into our long term forecasts given the ongoing competitive environment and slowdown in the rate of improvement in customer metrics,» said Mr Alexander, who expects Woolworths food margins to track around 4.8 per cent for the next few years compared with 4.4 per cent in 2017. (afr.com)
A positive delta means that the option position will rise in value if the stock price rises, and fall in value if the stock price falls (usually a call). (thecollegeinvestor.com)