NEW YORK (TheStreet) -- In money matters, you may want to call millennials modern traditionalists. The generation born between 1980 and 2000 likes banking online but still wants to be able to walk to a neighborhood branch, according to a Goldman Sachs (GS) - Get Report study.

Millennials' desires are important, and likely to become more so, because the population group is the largest in U.S. history -- numbering about 92 million. The segment has already transformed consumer retail, media and technology, New York-based Goldman says, and finance is next.

"By 2038, millennials will become the most important financial generation in America," said the bank, which interviewed 752 millennials over 18, with responders split almost evenly between men and women as well as younger and older millennials. "The industry will have to adapt to meet their needs."

The desire for a local branch, for instance, may prove significant to major banking companies as many are closing brick-and-mortar sites to focus on less costly digital services.

The number of local offices at the four largest U.S. banks -- JPMorgan Chase (JPM -Get Report), Bank of America (BAC - Get Report), Wells Fargo and Citigroup (C -Get Report) -- has dropped almost 4% to 19,747 in the past two years. Mobile businesses at the companies expanded 32% in the same period. Wells Fargo, meanwhile, has added 34 branches.

For millennials, having a branch close to their home or office was second only to a bank's reputation and values when choosing where to put their money. Mobile and online platforms ranked fourth.

Despite the industry's increasingly technological emphasis, the branch remains a symbol of safety and security for customers, Wells Fargo CEO John Stumpf said during a conference in May

"Most millennials open up their first checking account with a branch that was within 2 miles of where they grew up, even if they live some place else," Stumpf said. About "75% of our customers, millennials included, visit our branches once every six months."

In Goldman's survey, the age split in the population sample provides perspective on how attitudes within a generation may be shaped by demographic factors. For example, regardless of whether you're a Boomer, Gen-Xer, or Millennial, your views on money likely change between the years of 18 and 34.

While the survey also showed that millennials are likely to use payment services such as Venmo, Apple Pay, and Square, the majority of their transactions are still handled through traditional financial companies such as banks, Visa (V) - Get Report and Mastercard (MA) - Get Report, Goldman Sachs found.

The new entrants still have room to grow, though, as Paypal, a relatively recent entry, is now tied with traditional banks in how millennials handle payments. Paypal was founded in 1998 and went public in 2002

For all their openness about new systems, there is one in which most millennials have no interest: bitcoin. Fifty-one percent of respondents said they have never used the digital currency and have no plans to do so.