I want to implement some kind of confidence measure for my stock prediction model, which predicts the next day's trend (whether the price would rise or fall). As in, a trade order should be placed only if the model is certain about its prediction up to some degree. Now decision_function() does provide a confidence measure but I can't use it, as a threshold cannot be set without actually seeing the decision_function() values of test instances.
Scikit-learn's documentation of SVC says that there are some "theoretical issues" with Platt Scaling - the method used to obtain prediction probabilities of classifiers.
Is it okay to use predic_proba() as a confidence measure?