But is has also highlighted how management consultancy groups exploited Wall Street's collective paranoia about ceding ground to rivals building up big businesses during the boom years.
It emerged on Wednesday in testimony before the Financial Crisis Inquiry Commission in Washington that, partly on the back of a 2005 Oliver Wyman analysis of potential growth in the fixed-income market, Citi decided to ramp up its business in collateralised debt obligations, or CDOs, backed by high-risk or "subprime" mortgage loans.
This ultimately led to a US government bail-out after Citi racked up more than $50bn in losses in the wake of the implosion of the subprime market.
In the heady pre-crisis years, firms such as Oliver Wyman and McKinsey were frequently called in to assess how banks could bolster profits in underperforming divisions, as bank executives looked to stave off shareholder complaints about lagging returns.
Oliver Wyman, for example, marketed a yearly analysis of how banks were faring relative to each other in hard-to-measure areas such as fixed income and commodities, offering previously unavailable competitive intelligence.
Citi was not the only bank that increased its exposure to CDOs at an inopportune moment. UBS was singling out structured credit and securitised products as big opportunities for growth as late as March 2007, again partly on the back of a strategic review of its fixed-income business led by Oliver Wyman.
In a 50-page report into the Swiss bank's near-collapse, published in April 2008, UBS revealed that the consultancy group "recommended that UBS selectively invest in developing certain areas of its business to close key product gaps, including in credit, rates... subprime and adjustable- rate mortgage products."
Oliver Wyman repeatedly declined to comment on either report, citing client confidentiality.
But people familiar with the analysis provided to Citi say it included ample warnings about the risks of diving into the structured product market, as well as other precautions that should be considered.
Citi insiders say that those precautions may have been overlooked amid mounting pressure on senior executives within Citi's midtown Manhattan headquarters and at 388 Greenwich Street, the downtown home of the company's investment bank.
By 2005, whatever honeymoon Charles Prince had enjoyed in the two years since he succeeded Sandy Weill as the bank's CEO was long gone, and investors had become increasingly vocal in questioning whether the financial-services conglomerate's growth could keep pace with either large US commercial lenders, including Bank of America, or stand-alone securities firms such as Goldman Sachs and Lehman Brothers.
Citi's consumer businesses had stagnated; reviving them meant spending billions of dollars in acquiring regional lenders or opening new branches, and it would take years to reap fully the benefits of those investments - time Mr Prince did not have. His easiest option was to depend on Citi's investment bank, specifically on a fixed-income franchise whose core came from the once-dominant bond trader Salomon Brothers.
Relying in part on the Oliver Wyman study, Robert Rubin, then chairman of Citi's executive committee, and Thomas Maheras, head of capital markets, conducted a review of the fixed-income business. They then sought Mr Prince's approval for an ambitious investment plan to ensure Citi would keep its edge as the debt markets evolved.
Citi would end up spending more than $300m in 2006 to hire traders, bankers and cutting-edge software systems. CDOs and other structured credit products were a part of that build-out.
Based in part on a careful study from outside consultants hired by our senior-most management, the company decided to expand certain areas of our fixed income business that we believed at the time offered opportunities for long-term growth.