The S&P 500's seemingly unstoppable rally has put some investors on edge, but Dennis Gartman's mantra is simple when it comes to U.S. stocks: the trend is your friend.
"It's still a bull market. Sometimes one has to take a simplistic perspective and look at the charts and ask what direction is it moving in? How would a four year old look at this?" Gartman, founder and editor of the closely-watched The Gartman Letter, told CNBC on Monday.
"A four-year-old would look at the chart and say I'm not sure what it is, but it's moving from the lower left to the upper right. We try to look too deeply into things, sometimes it's better to look at what the major trend is. As we make new highs, the trend is still to the upside in equities," he said.
U.S. stocks scaled fresh heights last week, with the S&P rising to a record high of 2,096.99 on Friday as a bounce in oil prices boosted energy shares.
It's been six years into the bull market, and investors are naturally concerned about how long the good times will roll. Dollar strength and weak global economy have been cited as potential stumbling blocks by market bears in recent months. Regardless, bulls have remained in the driver's seat.
"Yes, there are reasons to be nervous about it [the rally] and yes there's a likelihood of a correction along the way, but anybody who has tried to sell the stock market has proven to be utterly and completely wrong," he said.
Oil: Dead cat bounce
Gartman believes the recent rebound in oil is nothing but a "solid short-covering bounce" and expects prices to re-test lows reached at the end of January.
"Markets rarely make neat bottoms, especially markets that are as important as crude oil. [They] tend to go down and retest those lows and my bet is that's exactly what's going to happen," he said.
U.S. crude has risen over 20 percent from the low of $44.08 a barrel it set on January 28. "Crude oil is still being pumped aggressively, and yes rig counts are down, but we're still producing more than we were a mere six months ago," he said.
To trade the abundance of supply, Gartman recommends investing in companies that operate oil tankers.
"We're filling up the tanks in the middle of the U.S. and soon we're going to be filling up tankers in the ocean. Tanker rates are starting to rise, even though the Baltic Dry Index continues to make new lows," he said.
The Baltic Dry Index, which tracks rates for ships carrying bulk commodities, is at its lowest level in around three decades.
Responding to reports that Apple is making a foray into the automobile space, Gartman says such a move would be overstepping boundaries.
"It's one thing to produce a software (and) hardware, it's entirely another to produce an automobile," he said. "To me this is Icarus flying far too close to the sun."
On Friday, the Financial Times reported that Apple is recruiting experts in automotive technology and vehicle design to work at a new top-secret research lab.
Dozens of Apple employees, led by experienced managers from its iPhone unit, are researching automotive products at a confidential Silicon Valley location outside the company's Cupertino campus, FT said, citing several people familiar with the company.
"This is a very poor decision. But I've been wrong on Apple in the past and may be wrong on it again."