Investing at the intersection of financial services and technology can be a lucrative endeavor. Companies operating here, such as Block (XYZ -0.40%) and SoFi Technologies (SOFI 3.73%), provide critical products and services to their customers. And they're staring at tremendous growth opportunities.Both have their merits, but which of these fintech stocks is the better buy right now?  Block: Serving merchants and individuals with a Bitcoin twistBlock (originally known as Square) started out selling a small c ...