(Reuters) - The trial of Sung Kook "Bill" Hwang kicks off with opening statements in Manhattan federal court on Monday on charges stemming from the 2021 collapse of his $36 billion fund Archegos Capital Management.

The case has been closely watched as a test of prosecutors' ambitious market manipulation theory, and because it is expected to shed light on the inner workings of Wall Street's dealings with profitable but risky clients.

Testimony in the trial, which could last up to eight weeks, will center on the implosion of Hwang's lightly regulated family investment office Archegos, which prosecutors allege caused more than $100 billion in shareholder losses at companies in its portfolio.

Prosecutors accuse Hwang of using financial contracts known as total return swaps to secretly amass outsize stakes in multiple companies without actually holding their stock.

His positions were so large they eclipsed that of the companies' largest investors, driving up stock prices, prosecutors say. At its peak, they say, Archegos had $36 billion in assets and $160 billion of exposure to equities.

Falling stock prices in March 2021 triggered margin calls that Archegos was unable to meet. That, in turn, led some banks to dump the stocks backing his swaps, causing big losses for Archegos and its lenders, such as Credit Suisse, now part of UBS, and Nomura Holdings ( NMR ).

Prosecutors claim Hwang and former Archegos Chief Financial Officer Patrick Halligan, who is also on trial, lied about their holdings to sustain their business relationship with global banks.

Hwang and Halligan are charged with racketeering conspiracy. Hwang faces an additional 10 counts of fraud and market manipulation, and Halligan an additional two counts of fraud. Each count carries a maximum potential sentence of 20 years.

The two men have pleaded not guilty and are expected to argue prosecutors are pushing a novel and nonsensical market manipulation theory.

A jury of seven women and five men were chosen last week.

Hwang's lawyers have described the case as the "most aggressive open market manipulation case ever" brought by prosecutors. Several attorneys told Reuters it may be a tough case for the government.

Archegos head trader William Tomita and Chief Risk Officer Scott Becker have pleaded guilty to related charges and are expected to testify at the trial. Some bank executives may also appear on the witness stand.

(Reporting By Brendan Pierson in New York)