At the end of this week, Bear Stearns is apparently finding itself a victim of rumors turned to reality.

Plagued by persistent speculation that the investment bank was lacking cash, Bear Stearns persistently denied that was the case. But by Friday morning, the firm had apparently suffered enough damage that it announced that it had sought a financial lifeline: credit facilities from the Federal Reserve Bank of New York via JPMorgan Chase.

It’s worth examining how over the past week, an already weakened Bear nearly succumbed to repeated questions about its financial health.

The rumors began in earnest on Monday, as whispers circulated that Bear faced a liquidity crisis linked to the still-dropping value of mortgage-backed securities an affiliate had issued. Though most of its bigger rivals have also taken write-downs related to those investments, Bear had long ago become the embodiment of the mistakes of the subprime mortgage era. Despite repeated assertions that it had enough capital, Bear-issued securities remained subject to credit rating downgrades.

The swell of rumors prompted Bear’s chief executive, Alan D. Schwartz, to issue a terse statement late that day: “Bear Stearns’ balance sheet, liquidity and capital remain strong.” But shares in the firm closed down 11 percent at $62.30.

To back up Mr. Schwartz’s statement, the Securities and Exchange Commission stepped in. The agency’s chairman, Christopher Cox, told reporters on Tuesday that the regulator was reviewing capital levels at the five big investment banks on a constant basis. “We have a good deal of comfort about the capital cushions that these firms have been on,” he said. That seemed enough to stanch the speculation: Bear’s stock rose slightly to close at $62.97.

By Wednesday, the firm took a more decisive step. Mr. Schwartz spoke with CNBC’s David Faber that morning, saying that Bear’s holding company ended last year with a $17 billion liquidity cushion, which is “virtually unchanged” so far this year. Bear’s stock dipped 2 percent to $61.58.

The situation changed by Thursday. Inchoate speculation gained tangibility as reports from the likes of the Wall Street Journal outlined potential blows to Bear’s stability. The Journal reported that several firms regarded Bear as a potentially risky counterparty, with some clients going to far as to request that Goldman Sachs, Morgan Stanley and others serve as counterparties to Bear on several transactions. And hedge funds that use Bear as a primer broker — a provider of services like clearing trades — had shifted some of their business to other shops, the Journal said.

By that point, it seemed less clear whether these investors and clients had seen proof that Bear was suffering a liquidity crisis, or were simply reacting to a growing wave of pessimism and fear. Bear’s stock closed down 7.4 percent at $57.

Whether the rumors were true had become almost irrelevant by Friday. In his statement announcing the emergency financing, Mr. Schwartz said that while his statements over the past week had been truthful, “our liquidity position in the last 24 hours had significantly deteriorated.”

Bear’s stock was down about 39 percent by noon on Friday, trading at $34.75.