Microinvesting app Stash is doubling its 120-person team to support its move into banking and financial planning products, including those that help its customers invest on behalf of their kids. It's using a $37 million Series D funding round led by Union Square Ventures to perfect its new investment account for parents of minors, which launched Monday, and build its checking account it plans to launch sometime this year. "We've always had the same mission of getting people off the sidelines. You can't just try to build the next JPMorgan," said co-founder and president Ed Robinson. "We build deep relationships with our customers... but we're broadening our offering to continue to help." Stash's strategy echoes a wide-reaching trend in financial services, in which single-product companies diversify their offerings to keep a loyal pool of customers, thereby blurring the lines between personal finance, lending and investment platforms. Personal finance apps MoneyLion and Credit Sesame are now offering investment products, for example, and lending startups like SoFi and Marcus by Goldman Sachs have shown more interest in customer checking accounts. Stash currently has 1.7 million customers, with an average age of 29 and annual income typically under $50,000, and there's been a "huge" request from them for Stash to help them even more with their financial lives across the gamut, Robinson said. It's also going to improve its existing products with the new funding. Last year, Stash launched a retirement savings product and a virtual assistant called "Stash Coach," which delivers personalized, data-driven insights based on transaction activity similar to the way banks are experimenting with Alexa or Bank of America with its AI-assistant erica. That means Stash is hiring; specifically, it's looking for new engineers and product and marketing staff, though he declined to specify the plans further. For investment and personal finance apps, diversifying products keeps customers tied to the platform and it creates cross-selling opportunities. Companies that want to monetize on a single product offering have struggled to grow market share. More and more, the solution to that is to offer a more complete suite of financial products and services, regardless of a company's entry point. "There’s definitely that sense that being a full service banking institution is much more fruitful in creating a customer for life," Luvleen Sidhu, president and chief strategy officer of BankMobile, told Tearsheet last month. "The beauty of banking is every customer is a potential customer. Every person needs a bank and it’s one of those products everyone is in need of so there’s room for ample competition. You have to always look at what value you’re providing." But Stash maintains its expansion is just a response to customer demand, based on user feedback. "We offer education for these users to help them build the right financial habits from day one, and that doesn't just stop at investing," said Robinson. "Our mission is to help our users throughout their whole financial lives."