In recounting the decision to put all of their savings into the campaign, Mr. Cruz said in the 2013 Times interview that Mrs. Cruz immediately agreed to his proposal, even though he was trailing in the polls and still viewed as a long shot against Lt. Gov. David Dewhurst, who spent $24 million of his own money on the race.

“What astonished me, then and now, was Heidi within 60 seconds said, ‘Absolutely,’ with no hesitation,” Mr. Cruz said.

Mrs. Cruz, who is on leave as a managing director at Goldman Sachs, later suggested that the reality was more complicated. She told Politico in 2014 that she thought they should apply “common investment sense” and not use their own money for the campaign “unless it made the difference” in winning. The article did not mention anything about loans from banks.

The money from the Cruzes allowed his campaign to keep running television ads in the period preceding the primary election, including a $300,000 ad buy that highlighted the story of Mr. Cruz’s father’s flight from Cuba in the 1950s after opposing the Batista regime. Mr. Cruz earned enough votes in the primary to qualify for a runoff, where he defeated Mr. Dewhurst and went on to win the general election.

The ethics reports that candidates file with the Senate require them to list all assets they held at the close of the year or that generated income during the year. Assets are reported in broad categories of value, such as $1,001 to $15,000 and $100,001 to $250,000.

Mr. Cruz’s filings show that at the close of 2011, he and his wife had cash and securities in bank, brokerage and retirement accounts worth $1.3 million to $3.4 million. They also had mortgages and a loan against Mr. Cruz’s partnership equity in his law firm. During 2012, they sold securities worth $82,000 to $355,000, and the value of other holdings was reduced by, at most, $155,000.

However, they also added a money-market account with $250,000 to $500,000 in it, and the value of other holdings increased by as much as $435,000. All told, the value of their cash and securities in 2012 saw a net increase of as much as $400,000 — even as the Cruzes were supposedly liquidating everything to finance Mr. Cruz’s Senate campaign.