New Zealand shares ended marginally lower on Monday after markets digested worries over the independence of the US Federal Reserve.

The S&P/NZX 50 Index fell 0.1% or about 13 points to close at 13,683.29.

US Fed Chair Jerome Powell said the US central bank had received grand jury subpoenas from the Justice Department, raising the threat of criminal indictment in a sharp escalation of the Trump administration's campaign against the Fed, a Bloomberg report said on Monday.

"This is about whether the Fed will be able to continue to set interest rates based on evidence and economic conditions - or whether instead monetary policy will be directed by political pressure or intimidation," Powell said.

In domestic news, the end of 2025 saw December New Zealand property stock levels surpass 30,000 for the first time in any December in a decade, capping off a full year of consistently high supply, with more than 30,000 properties on the market every month of 2025, data from realestate.co.nz showed.

Also, national average weekly rent dropped 2.4% to NZ$626 per week in December 2025, with Central Otago Lakes District being the most expensive place to rent in New Zealand by more than NZ$200, according to a realestate.co.nz report.

In corporate news, Rakon (NZE:RAK) received a takeover notice from Bourns, indicating the US-based electronics firm's intention to acquire all of the company's shares and its outstanding employee share rights for cash consideration of NZ$1.55 each.

SKY Network Television (NZE:SKT, ASX:SKT) appointed David Mackrell as chief financial officer, effective Monday, succeeding Andrew Hirst.