Interpretation of second difference of a predictor


can you please help with this -
If I have a regression equation to predict Y using one of the independent variables which uses the second difference transformation, how can I interpret this in business sense. For instance if I am forecasting GDP of a country using S&P 2nd difference, what is the interpretation in theoretical sense
Yous said earlier: " using S&P 2nd difference". How is that "the change in absolute changes"? You would need to state clearly what's going on.
To some extent, the second difference is measuring whether the companies have generated more casfflows than last year or less.