Hmmm.
'The Guardian is part of the Guardian Media Group, owned by the Scott Trust.[6] The trust was created in 1936 to "secure the financial and editorial independence of The Guardian in perpetuity and to safeguard the journalistic freedom and liberal values of The Guardian free from commercial or political interference".[7] The trust was converted into a limited company in 2008, with a constitution written so as to maintain for The Guardian the same protections as were built into the structure of the Scott Trust by its creators. Profits are reinvested in its journalism rather than distributed to owners or shareholders.'
https://en.wikipedia.org/wiki/Scott_Trust_Limited
'In February 2010, the company announced the sale of its GMG Regional Media arm and its regional print titles to the Trinity Mirror Group'
'Guardian News and Media, a subsidiary of the Scott Trust Limited, reported a loss of £30.9 million for the year to the end of April 2013'
Then they sold off Auto Trader.
'as of 1 April 2018, the value of the Scott Trust Endowment Fund was £1.01 billion, down slightly from £1.03 billion in 2017.'
It's funded by this Trust, as far as I can tell.