Barry Ritholtz, chairman of Ritholtz Wealth Management, thinks stocks are entering a "new secular bull market" following the "great secular bear market of 2000-13."

Writing in The Washington Post, Ritholtz offers several reasons for his prediction.

• Stock prices. "By spring 2013, most major U.S. stock markets and indices had broken above their previous range. All-time highs soon followed," he explains.
• Economic expansion. The recovery has been sluggish over the past five years, much weaker than normal. "Still the market has powered higher," Ritholtz notes. "As the economy continues to slowly heal, it should" lift earnings, boosting stocks.
• Disbelief in the rally. Many experts are skeptical of stocks' gains, just as they were in the early 1980s ahead of the last secular bull market.

To be sure, don't be shocked to see a 15 to 20 percent correction at some point, Ritholtz says.

But, "if historical patterns hold true, and this is a new secular bull market, it could last another decade or more."

As for the short term, investors see plenty of reasons for bullishness.

"The numbers in the third quarter showed a steady economy, we continue to have oil below $80, consumers feeling confident, low interest rates, and that's a combination that works well for stocks," Mark Kepner, an equity trader at Themis Trading, tells Bloomberg.

"Central banks have also been quite accommodative in what they've been saying, and it seems to be working."

Related Stories:

• Piper Jaffray's Johnson: 'Bull Market Is Just Starting'
• Yardeni: Bull Market Is Alive and Well