What a couple of days for shareholders of Amazon.com (AMZN, news, msgs). And what a couple of days for company founder and CEO Jeff Bezos. It was like the 1990s again.

Amazon shares soared nearly 27% Wednesday, from $44.75 to $56.81, after the company reported that first-quarter profits doubled from a year ago.

The shares jumped an additional 10.5% on Thursday, to $62.78. The total gain for Amazon.com over the two days: 40.3%.

The two days' gains boosted the company's market capitalization -- the value of all the shares trading in the public domain -- from $18.3 billion to $25.7 billion, a gain of about $7.4 billion.

For Bezos, who started Amazon.com in 1994, that meant the value of his 101.3 million shares in the company jumped in value from $4.53 billion to $6.36 billion, a gain of roughly $1.8 billion.

Wednesday's gain was its fourth-largest one-day percentage gain. The two-day percentage gain was the third-largest in the company's history. The larger two-day gains:

• A 43.4% gain between April 9 and April 10, 2001, when the stock closed at $12.01.

• A 42% gain between Nov. 22 and Nov. 23, 1998, when the stock closed at $36.33.

His is a volatile stock

His net worth has been all over the place from $10.1 billion in 1999, according to Forbes, to $1.5 billion in 2002. Last year, Forbes said he was worth $4.3 billion.

Amazon's closing price on Nov. 23, 1998, after that 42% gain, was $36.33, adjusted for splits.

The stock peaked a year later -- on Dec. 10, 1999 -- at $106.69. Then, the stock lost 94% of its value over roughly the next 22 months before bottoming at $5.97 on Sept. 28, 2001. Since then, the stock is up 951%.

Over its first seven years as a publicly traded company, Amazon.com lost nearly $3 billion on total revenue of $12.2 billion.

In the last three years, its profits have totaled nearly $924 million on total revenue of $20.7 billion.

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