LOS ANGELES (CBSLA.com) — Confusion erupted on Wall Street Monday night when it appeared Amazon’s stock dropped more than $800 in after-hours trading while several others showed dramatic gains and losses.

It appears everything is back to normal, but as CBS2’s Andrea Fujii reports, many people were surprised to see the wild fluctuations.

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Google, Yahoo! Finance and Bloomberg were some of the sites that showed the changes.

Apple appeared to be down 14 percent, Google down 86 percent and Microsoft up 79 percent — all were trading at $123.47

Nasdaq says it was a mistake that occurred due to misuse of test-data sent out to different sites. But for a while, investors on Twitter were concerned.

Kevin Lane tweeted: “Something is wrong with a Nasdaq aggregator and now all your stocks are worth 123.47.”

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Dan Goldie wrote: “Go home Nasdaq, you’re drunk.”

David Rae, President of DRM Wealth Management, says it’s not uncommon for computer glitches to happen; he warns investors not to act impulsively.

“If you see a bunch of prices of major companies all the same exact price to the penny, something is probably wrong,” he said.

“Don’t freak out,” he advised. “If you get something that doesn’t sound right just take a deep breath. Don’t go sell anything. If you hear Apple has tanked 75 percent something has probably gone wrong.”

Nasdaq says they are investigating what happened.

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Prices on the actual Nasdaq site were not affected and no actual trades were completed at those incorrect prices.