How trillion-dollar millennials are spending their cash

With a spending power hitting trillions of dollars, millennials are fast becoming a force to be reckoned with in the market. But experts and analysts are raising concerns whether all this power is being used wisely and companies are harnessing that buying power.

Millennials, those born between the early 1980s and the early 2000s and also known as Generation Y, are estimated to have a combined global spending power of $2.45 trillion in 2015, according to research by Youbrand. However, this generation has also grown up against a backdrop of austerity and financial uncertainty, meaning that young people—and their cash—are pulled often in opposite directions between consumption and aspiration and wanting to play it safe.

Indeed, 18-to-34-year-olds tends to be more burdened with debt and asset-light than their parents' generation, making them more fiscally conservative, according to research by investment banks.

Millennials and money

Sarbjit Nahal, head of Thematic Investing at Bank of America Merrill Lynch, told CNBC just how important the spending power of millennials will become in the near future.

"We very much think of this as an American phenomenon but from a demographic perspective, there's 2 billion millennials around the world and 86 percent of them are living in emerging markets, and in Brazil, India and China they've overtaken the number of boomers (born in the post-war years)," Nahal said Monday.

"It's (all about) the incredible spending they have, if you look at the U.S. they are the most important group in terms of the workforce and by 2018 they're going to overtake the boomers and by 2025 we're looking at over $8 trillion worth of annual net income."

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Nahal said that the millennial generation was extremely tech savvy and price conscious—a clear signal to companies looking to make money from this generation with tech-savvy retailers beating more traditional retailers, such as department stores.

"When they make a consumer purchasing decision, it's price they're looking at. They've grown up under very difficult economic times, and secondly, they're looking for convenience."

Millennial consumers

Generation Y itself can be split into two—with the 18-to-25-year-olds often studying or living at home with parents and the upper age bracket from 25-34 is often making aspirational big-ticket purchases, such as houses and cars.

As such, young people are taking far more interest in their own finances and companies have sprung up to take advantage of the discerning generation.

Having seen the destruction that the most recent financial crisis in 2008 wrought on global economies—and those that have affected their parents' generation previously, both BoAML's Nahal and Future Finance's Norton believe Generation Y was more cautious about debt.

Brian Norton, chief executive and founder of Future Finance, a specialist student loans provider in the U.K., told CNBC on Monday that Generation Y was more inquiring when it came to assessing his loan product.

"There's a desire to become something of an expert in the product, which I think is new," he told CNBC's "Squawk Box."

Norton said his loans company, which says it can "bridge the funding gap between government loans and the actual cost of attending university," has high standards before lending to students.

"We're not subprime at all, our standards are quite high," he said. "(With us) students make small repayments while they're in university and then have 10 years to repay the loan from when they graduate but with a typical consumer loan from a bank you'd be repaying over three to five years and start making full payments immediately which doesn't work for students."

Keen entrepreneurs

Despite the risks of borrowing, many millennials are keen to start up their own ventures. According to Ethan Senturia, chief executive of DealStruck, which offers small business loans up to $250,000, young people make confident entrepreneurs.

"I think millennials ... certainly have learned lessons from the past in terms of how to be a prudent borrower and finance their companies appropriately, but they're generally optimistic and believe they can achieve success," Senturia told CNBC's Worldwide Exchange.

"Their biggest concern has more to do with managing their own business and making sure they make the best decisions. Most millennials who are entrepreneurs have to focus on the things they control, like how they cost their projects and how they invest and try not to worry too much about the macro—because there's only so much they can do about it."

- By CNBC's Holly Ellyatt, follow her on Twitter @HollyEllyatt. Follow us on Twitter: @CNBCWorld