NEW YORK ( TheStreet) -- Goldman Sachs ( GS) will see a big hit to earnings and revenue next year as a result of a new rule being crafted by regulators, even if the most lenient terms are adopted, according to a JPMorgan ( JPM) analysis. Kian Abouhossein, an analyst with JPMorgan-Cazenove who covers investment banking, estimates that Goldman's revenue could plummet 46% in 2012 if the Volcker rule is implemented in a strict fashion, with earnings set to decline 15% this year, even if the regulation's scope is limited. The Volcker rule - officially known as Section 619 of the Dodd-Frank financial reform bill - is meant to lessen the risk to taxpayers and depositors by barring large banks from trading capital from their balance sheets for the express purpose of earning money. It will also restrict banks' investments in hedge funds and private equity firms and perhaps put a tighter watch on venture capital as well. Regulators at the Securities and Exchange Commission and Commodity Futures Trading Commission are working to define what, exactly, is included within the realm of "proprietary trading." Investment banks have not just traders who trade for the bank's bottom line, but others who take positions in securities and commodities to provide clients with liquidity. The latter function is known as market-making. Goldman is widely held as the big U.S. bank with the most exposure to the Volcker limits. The bank is working to replace trading revenue with other types of business, though it is likely to take some time. "Goldman is the best-in-class liquidity provider today, but potentially has the most to lose from the new regulation," said Abouhossein. Other firms will see earnings and revenue decline as well. While CFO David Viniar has said that pure prop trading accounted for a "10-ish type of percent" of Goldman's business in recent years, it represented less than 2% of revenue at both Citigroup ( C) and Bank of America ( BAC), and slightly more at JPMorgan Chase, all of which have big consumer banking businesses and Wells Fargo ( WFC) barely has a presence in that area.