In 1995, Yukos was one of Russia’s largest oil producers. But the newly privatised company faced a Soviet legacy of outdated financial management and chronic underinvestment: oil production was falling by 15%, the company owed debts of around $3 billion and at the same time struggled to collect what was due from its creditors - the biggest creditor being the Russian State. Yukos's workers had not been paid for months. The economic shocks of 1998, when the rouble and stock market collapsed, only made things harder.
But the company underwent internal restructuring, invested heavily in new technology and assets, boosting oil production and efficiency. It adopted Western standards of governance, issued quarterly financial reports in line with US GAAP, and published its entire ownership structure. You can see the ownership structure as disclosed during the arbitration proceedings here.
By 2003, Yukos was the country's largest taxpayer, accounting for 5% of the federal budget, employing 100,000 people across 50 regions, and reaching a market value of more than $33 billion. Yukos joined the Financial Times top ten global companies for shareholder confidence.