Tom Lee: Investors should tune out Greece noise

Developments in Greece and China bear watching but will have limited or no effect on the U.S. economy or markets, perennial bull Tom Lee said Monday.

Global markets were broadly lower Monday, a day after Greeks voted against a bailout package put forward by Greece's creditors and as Chinese officials took measures to prevent a full-blown stock market crash.

"I think what we're overlooking is that turmoil in Europe has natural buffers in the U.S.," Lee told CNBC's "Squawk on the Street." "I really think that investors who are focused on the U.S. have to tune out some of the short-term noise and realize it's not going to really change things at year end."

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Investors seeking relative safety will pile in the United States, strengthening the dollar and bolstering asset flows, said Lee, founder of Fundstrat Global Advisors. The Federal Reserve may also hold off raising its benchmark interest rates due to adverse developments overseas, which would also protect asset prices, he added.

Lee also sees reasons to be optimistic in the U.S. housing market and recent procurement and supply chain data from the Institute for Supply Management. At the same time, easy money policies in Europe and China are creating "positive developments" for pent-up demand and labor markets in the United States, he added. "I think there's an organic recovery now taking place in the U.S."

Jay Bryson, global economist at Wells Fargo Securities, said it was impossible to say with 100 percent confidence the situation in Greece and China would not impact U.S. markets.

"If Greece leaves the euro zone and the euro zone starts to wobble a little bit, that's going to continue to have financial market repercussions around world," he told "Squawk on the Street."

Weakness in China and Europe could potentially slow down U.S. exports and damp down the dollar, he added. "We're in uncharted territory here. There are lots of unknowns out there, lots of moving pieces, and I think investors really need to keep an eye on what's going on here."

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Earlier Monday, analyst Peter Boockvar said Greece may be a "sideshow" in the international economy, but developments there could exacerbate the biggest risk to global assets.

Investors have recently seen a global rise in interest rates, which could put pressure on U.S. stocks, which were "very expensive," said Boockvar, chief market analyst at the Lindsey Group.

"To me, Greece is sideshow to the global rise in interest rates that we've seen," he told CNBC's "Squawk Box." "Let's just say that Greece is temporarily solved, interest rates are going to start heading higher again, and to me that's the risk to global asset prices."

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Higher interest rates present an alternative to stocks for investors. When rates run up significantly, it can lead to a flight from equity markets.

Greece's "no" vote on new austerity was largely symbolic because the proposal was no longer on the table, but it moved Greece closer to default on an European Central Bank loan and signaled a potential first step toward its exit from the 19-nation euro zone.

While the U.S. 10-year Treasurys fell to 2.3 percent Monday, Boockvar noted that the yield went from about 1.85 percent to 2.5 percent between the end of January and the end of June.

Further uncertainty over the outcome in Greece and the broader euro zone would presumably lead investors to demand higher yields on the continent's debt to offset the risk of holding those assets.

Greek banks remained closed and capital controls in place ahead of a European Central Bank meeting Monday on emergency lending to the country and a summit of European Union leaders set for Tuesday. The ECB froze increases to emergency lending last week after Greek Prime Minister Alexis Tsipras called the national referendum.

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Greece has a 3.5 billion euro payment due July 20 on a bond held by the ECB. It entered arrears last week after failing to pay 1.6 billion euros on a bond held by the International Monetary Fund.