Testimony from defendants in Enron's fraud and conspiracy case ended on Monday, after the defence reduced the number of witnesses to testify.
Mr Lay insists he told the truth
The defence rested in the 15-week trial after cancelling two witnesses. Jury deliberations are to start next week.
Enron's founder Kenneth Lay and former chief executive Jeffrey Skilling were positive on leaving court.
They maintain they told the truth about the state of the energy firm, but the government insists they lied.
"We feel real good. We think... we're going to prevail," Mr Lay said on Monday.
Conspiracy and fraud charges
The firm suddenly collapsed in 2001 facing debts of $332bn (£180bn) while Mr Lay was chief executive.
The US government says Mr Lay and Mr Skilling gave an overly positive picture of Enron, all the while aware that accounting tactics were falsely propping up the firm.
Both Mr Skilling and Mr Lay were among 29 witnesses selected by the defence.
The prosecution, whose witnesses includes eight former Enron executives pleading guilty, had rested on 28 March.
Over the six days that Mr Lay testified, he insisted he had been telling the truth when he told Enron employees and investors about how strong the firm was in late 2001.
But in response, the prosecution said Mr Lay had been given written warnings by employees about the firm's accounting situation.
1985 - Enron formed
October 2001 - Enron reports $638m third quarter loss and $1.2bn fall in shareholder equity
October 2001 - Securities and Exchange Commission begins inquiry into firm
November 2001 - Enron shares sink to 10-year lows as buyout deal falls through and further losses are revealed at the firm
December 2001 - Enron files for Chapter 11 bankruptcy
2002 - Criminal investigation of Enron launched
2004 - Skilling and Lay charged over Enron collapse. Former finance chief Andrew Fastow pleads guilty to criminal charges and agrees a 10 year jail term
January 2006 - Enron trial begins
Similarly, Mr Skilling said he had not lied when he openly talked about the firm's strength.
Mr Skilling defended accounting structures that the government has said falsely boosted earnings.
In total, Mr Lay is being charged with six cases of conspiracy and fraud. Mr Skilling is being charged with 28 accusations of conspiracy, fraud and insider trading.
If convicted both men would face prison.
The defence and the prosecution are due to start presenting their closing arguments on 15 May, before a jury comprising eight women and four men.
Mr Lay faces another bank fraud case, set to open on 18 May.