the goldman sachs group , inc .and subsidiaries management 2019s discussion and analysis investing & lending investing & lending includes our investing activities and the origination of loans , including our relationship lending activities , to provide financing to clients .these investments and loans are typically longer-term in nature .we make investments , some of which are consolidated , including through our merchant banking business and our special situations group , in debt securities and loans , public and private equity securities , infrastructure and real estate entities .some of these investments are made indirectly through funds that we manage .we also make unsecured and secured loans to retail clients through our digital platforms , marcus and goldman sachs private bank select ( gs select ) , respectively .the table below presents the operating results of our investing & lending segment. .
[['$ in millions', 'year ended december 2017', 'year ended december 2016', 'year ended december 2015'], ['equity securities', '$ 4578', '$ 2573', '$ 3781'], ['debt securities and loans', '2003', '1507', '1655'], ['total net revenues', '6581', '4080', '5436'], ['operating expenses', '2796', '2386', '2402'], ['pre-taxearnings', '$ 3785', '$ 1694', '$ 3034']]
operating environment .during 2017 , generally higher global equity prices and tighter credit spreads contributed to a favorable environment for our equity and debt investments .results also reflected net gains from company- specific events , including sales , and corporate performance .this environment contrasts with 2016 , where , in the first quarter of 2016 , market conditions were difficult and corporate performance , particularly in the energy sector , was impacted by a challenging macroeconomic environment .however , market conditions improved during the rest of 2016 as macroeconomic concerns moderated .if macroeconomic concerns negatively affect company-specific events or corporate performance , or if global equity markets decline or credit spreads widen , net revenues in investing & lending would likely be negatively impacted .2017 versus 2016 .net revenues in investing & lending were $ 6.58 billion for 2017 , 61% ( 61 % ) higher than 2016 .net revenues in equity securities were $ 4.58 billion , including $ 3.82 billion of net gains from private equities and $ 762 million in net gains from public equities .net revenues in equity securities were 78% ( 78 % ) higher than 2016 , primarily reflecting a significant increase in net gains from private equities , which were positively impacted by company- specific events and corporate performance .in addition , net gains from public equities were significantly higher , as global equity prices increased during the year .of the $ 4.58 billion of net revenues in equity securities , approximately 60% ( 60 % ) was driven by net gains from company-specific events , such as sales , and public equities .net revenues in debt securities and loans were $ 2.00 billion , 33% ( 33 % ) higher than 2016 , reflecting significantly higher net interest income ( 2017 included approximately $ 1.80 billion of net interest income ) .net revenues in debt securities and loans for 2017 also included an impairment of approximately $ 130 million on a secured operating expenses were $ 2.80 billion for 2017 , 17% ( 17 % ) higher than 2016 , due to increased compensation and benefits expenses , reflecting higher net revenues , increased expenses related to consolidated investments , and increased expenses related to marcus .pre-tax earnings were $ 3.79 billion in 2017 compared with $ 1.69 billion in 2016 .2016 versus 2015 .net revenues in investing & lending were $ 4.08 billion for 2016 , 25% ( 25 % ) lower than 2015 .net revenues in equity securities were $ 2.57 billion , including $ 2.17 billion of net gains from private equities and $ 402 million in net gains from public equities .net revenues in equity securities were 32% ( 32 % ) lower than 2015 , primarily reflecting a significant decrease in net gains from private equities , driven by company-specific events and corporate performance .net revenues in debt securities and loans were $ 1.51 billion , 9% ( 9 % ) lower than 2015 , reflecting significantly lower net revenues related to relationship lending activities , due to the impact of changes in credit spreads on economic hedges .losses related to these hedges were $ 596 million in 2016 , compared with gains of $ 329 million in 2015 .this decrease was partially offset by higher net gains from investments in debt instruments and higher net interest income .see note 9 to the consolidated financial statements for further information about economic hedges related to our relationship lending activities .operating expenses were $ 2.39 billion for 2016 , essentially unchanged compared with 2015 .pre-tax earnings were $ 1.69 billion in 2016 , 44% ( 44 % ) lower than 2015 .goldman sachs 2017 form 10-k 61 .

Question: in millions for 2017 , 2016 , and 2015 , what was the minimum amount of equity securities?
Answer: 2573