It's gaining momentum, and now might be the right time to buy.PayPal Holdings (PYPL 0.86%) might turn out to be one of the year's best turnaround stories. It started the year on a positive note, with a new CEO and trajectory, and so far PayPal stock is up 25% year to date.Let's see if that's likely to continue, and where PayPal might be at this time next year.Platform: ImprovingNew CEO Alex Chriss has a vision to transform PayPal from what he calls a "series of products and services" into a unified, complet ...