Investors are feeling good about the stock market's rally from April lows created after the bottom fell out when tariff plans were first announced.

Yet as investor emotions show a little more positivity, they are also more vulnerable to the idea that the rebound is nothing more than a bear-market rally, a brief bounce that could go away when the headlines change.

The Standard & Poor's 500 Index – which entered the year just under 5,900 -- set a record close at 6,144.15 on February 19 as it reacted to the release of minutes from the Federal Reserve Board's late-January meeting.

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The index-the most common proxy for "the stock market"-had fallen from that level by the time President Trump announced his tariff plans on April 2.

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