If you're looking for predictability in a year filled with surprises, consider this: JPMorgan Chase — the industry's largest bank by assets — has been a deposit-gathering machine.

It added $50 billion in consumer deposits from mid-2015 to mid-2016: those are nearly as many as held at a regional bank like Comerica or First Republic. Meanwhile, JPMorgan's mobile users grew by 18% in the second quarter from a year earlier, to about 25 million.

Other big banks set to report quarterly results over the next few days are expected to follow suit — Bank of America, Wells Fargo and perhaps more.

But gains for big banks may mean pain for their smaller competitors. As industry giants beef up their technology budgets, they are likely stealing market share from smaller banks, analysts said.

JPMorgan's deposit growth illustrates just one aspect of the ongoing — and occasionally contentious — divide between big and small banks. Recent surveys suggest megabanks have an advantage with consumers, especially as millennials seek out cutting-edge mobile apps.

"The strong gain in mobile usage is evidence of greater penetration into the consumer market," said Gerard Cassidy, an analyst with RBC Capital Markets.

Deposits in the company's consumer and community banking unit grew 10%, to about $586 billion, year over year. That included steady gains in each of the last four quarters, though the pace slowed in the latest quarter.

Overall, its deposits grew 3%, to $1.3 trillion.

Cassidy said JPMorgan's slick mobile offerings are a key driver of growth. He pointed to recent consumer surveys, showing that big banks are scoring higher on consumer satisfaction.

Community banks, on the other hand, are expected to fall behind when it comes to mobile users.

JPMorgan's digital operations "are outgrowing the industry," said Jeff Harte, an analyst with Sandler O'Neill.

JPMorgan is also benefiting from targeted growth in branches as well, Harte said. The company has added locations in affluent markets over the past year, including San Francisco and Miami.

Still, the company has trimmed its branch network overall. Total branches declined 3%, to just over 5,300.

"If you're looking for a Chase branch, they're everywhere," Harte said.

The marked growth in consumer deposits comes as JPMorgan — along with many of its largest rivals — makes splashy investments in technology.

During the second quarter alone, the company boosted its tech spending by 11%, to $1.6 billion, even as it slashed expenses overall. Over the past year, the company has launched a number of tech products, including a mobile wallet designed to compete with the likes of Apple and PayPal.

The growth also comes as JPMorgan continues to shift its focus to retail customers and shed higher-cost deposits. The company shrunk its deposit base by 6% in 2015, as it shed higher-cost commercial accounts.

Doing so helped the company reduce its capital surcharge to 3.5%. A year ago, the bank faced a surcharge of 4.5%, the highest level required by the Federal Reserve.

Throughout a call with investors Thursday, JPMorgan executives praised the company's consumer banking performance.

"The consumer business is firing on all cylinders," said Chief Financial Officer Marianne Lake, noting strong growth in auto loans, mortgages and credit cards.

She also said that, over the past year, the company has bolstered consumer deposits "more strongly than the industry."

But several analysts cautioned against reading too much into JPMorgan's consumer deposit growth.

Deposits are growing across the industry, as consumers stash their extra cash in their savings accounts and wait for rates to rise.

Personal savings rates, for instance, have recently been on the upswing, said Brian Kleinhanzl, an analyst with Keefe, Bruyette & Woods.

Additionally, a handful of small banks have boosted their deposit rates in recent months, attracting deposits with less sophisticated mobile apps.

Moreover, it is hard for experts to pin down which kinds of banks, community or regional, are the ones being hurt the most by the biggest banks' gains.

"We think that they are taking market share, but not necessarily from small banks," Kleinhanzl said, noting that evidence on the topic is mostly "anecdotal."

Overall profits at the $2.5 trillion-asset JPMorgan fell by 1%, to $6.2 billion.

Energy woes continued to weigh on the quarterly results, as the company boosted its provision for credit losses by 50%, to $1.4 billion. The higher reserves reflected the downgrade of one borrower, though executives declined to give the company's name.

Stock market volatility during the second quarter contributed to declines in revenue in the company's asset management and investment units. Its commercial and community banking units, however, reported profit gains of 5% and 6%, respectively.

During the call, executives were also pressed provide their thoughts on Brexit. JPMorgan has a large presence in the U.K., where it has about 16,000 employees and uses its operations there as a gateway to the European Union.

Jamie Dimon spoke out against Brexit before the June 23 vote to leave the European Union, describing it as a "terrible deal." JPMorgan may scale back its presence in the U.K. as a result, he said before the vote.

"We are hoping that the political leaders are very sensible," Dimon said Thursday, struggling to speak with a very hoarse voice. It is simply going to "take time to adjust to the new reality — which we don't know what it is."