Wall Street firms recorded their best first half in a decade as profits rose 11%, but a slowdown in the global economy and ongoing trade tensions could hit earnings in the second half of 2019.

This is according to a report from the New York State Comptroller.

Despite earnings rising, the amount set aside for compensation declined by almost 1% and bonuses in the second half of 2019 will depend heavily on revenue growth, according to the report. 

Profitability in the securities industry has grown for three years in a row, but growth in net revenue has slowed, reflecting weakness in certain business activities.  

"Volatile markets, global trade tensions, and political turbulence have sown economic anxiety and slowed global economic growth," state Comptroller Thomas DiNapoli said.

In addition to uncertainty around US-China trade talks, big companies are worried about how Brexit will affect Britain's standing with the rest of Europe.

Violent protests in Hong Kong and more recent threats from the White House about sanctions against Turkey for its invasion of Syria are also causing uncertainty.

Third-quarter results from big US banks showed weakness in their market-related businesses. 

US consumer business, however, remained strong, helping the banks beat market expectations for profit.

The securities industry, which accounts for 17% of New York City's economy, added 15,400 jobs in the city in the past five years. 
However, job gains in the early part of 2019 have been erased in recent months, the report said.

The current economic environment will continue to create challenges for the securities industry, the report added.