The last time venture capitalists invested this much money, the big tech names were Pets.com and Webvan.

Venture funding last year had its best year since the height of the dot-com boom, and Silicon Valley companies received nearly half of all the investments, according to a report released Friday. Venture firms in 2014 invested $23.4 billion in Silicon Valley-based tech startups, an 86 percent increase over 2013 and the best year since 2000, according to the MoneyTree report, produced by PricewaterhouseCoopers and the National Venture Capital Association.

“There’s lots of money out there and lots of people who want to make money,” said Mark McCaffrey, a software industry expert with PwC.

Why is the going so good in venture capital? Firms are raising a record amount of money — $29.8 billion last year, a 69 percent increase over the previous year and the largest gain in at least nine years — driven by the hot IPO market and lucrative returns, which makes more money available to startups, experts say. Also, hedge funds, mutual funds, Chinese investment groups and other wealth managers, which aren’t traditionally involved in these funding rounds, have thrown their dollars into the ring, driving up tech investments.

But the dollar bills aren’t raining down equally on all tech companies. Much of the funding in 2014 went to a small number of companies in outsize rounds that in some cases exceeded $1 billion.

“Not many more people getting money but those people who are, are getting much more money,” said Jeffrey Grabow, U.S. venture capital leader for consulting firm Ernst & Young.

If any of those startups fail, as startups tend to do, a lot of the money that poured into their coffers last year will be lost, and it could turn out that 2014 was the year of misguided investments, some venture experts say.

“It was a large year, but we won’t know for five or 10 years whether it was a good year or not,” said John S. Taylor, head of research for the National Venture Capital Association. “It certainly looks like good prospects out there, but the reality is you don’t know how this will work out until they IPO or they are acquired.”

Last year, there were 47 funding deals that exceeded $100 million, about three times the number in 2013. Silicon Valley — and San Francisco in particular — continues to be home to the largest deals, such as Uber’s twice-raised $1.2 billion rounds last year, which earned the company a $41 billion valuation, and Airbnb’s $475 million investment that propelled it to a $10 billion market value.

“We’ve never seen these deal sizes, ever,” McCaffrey said. “People are picking their investment and going big. … Someone is going to win, and someone is going to lose. If you’re wrong, you’re going to be at risk of losing that investment.”

But for now, the money valve is on full blast. Nationally, VC firms invested $48.3 billion in 2014, also the highest level since 2000, according to the MoneyTree report, which uses data from Thomson Reuters. Silicon Valley closed out the year strong with a $6.3 billion from VCs in the fourth quarter, the second-best since 2000. The report considers Silicon Valley to include the Bay Area as well as Santa Cruz and Salinas.

Despite the persistent and striking similarities, analysts say it’s not the dot-com bubble all over again.

“I don’t know that there are necessarily a lot of similarities,” Taylor said. “In 2000, companies went through the venture-capital process and went public before they had meaningful revenues and weren’t proven. That’s not true anymore.”

Unlike the dot-com era, the Internet isn’t a fandangled technology out of reach for many, and mobile technology is part of our daily lives, not some phenomenon forecasted for the future. While grocery delivery service Webvan failed in the dot-com bust, Instacart, the grocery delivery app launched in 2012, raised $220 million from investors in December and was expected to make $100 million in revenue this year.

But while some of the companies that VCs funded will go on to be tech titans, others are enjoying big investments they may not deserve.

In Silicon Valley, “it’s just a rising tide with a lot of boats,” said Deven Parekh of Insight Venture Partners. “A lot of small companies that because they are in Silicon Valley will get risen to an economic level they may not warrant.”

Contact Heather Somerville at 510-208-6413. Follow her at Twitter.com/heathersomervil.