It's difficult to take a material stake in Yahoo these days, said an RBC managing director, Mark Mahaney, on CNBC's "The Pulse" on Monday morning.

Mahaney — confident in the internet sector — voiced his skepticism over Yahoo amid news that Warren Buffett and Dan Gilbert had joined up to buy the troubled tech company.

"One of the biggest broad themes across the internet sector today is have-mores and have-lesses," said Mahaney. "We're seeing it in retail, travel and we're certainly seeing it in advertising. Almost 60 percent of global ad budgets are going to two names: Facebook and Google."

These tech giants continue to expand and generate revenue while Yahoo has had zero growth rate in advertising for five years.

"It's a very difficult investment," he said.

However, Mahaney is optimistic about other tech companies like Netflix and Yelp, which are both RBC's large and small cap "number one buys," respectively.

In particular, Netflix was able to achieve more than 10 percent of the household broadband markets all over the world.

"This is a global company, we've got 130 launches in the beginning of this year," said Mahaney. "These will take the time to build out, but they're gonna build out big. You want to buy it before the market realizes that."

Yelp, on the other hand, hit an "inflection point," said Mahaney, and saw a host of improvements, including a "reacceleration of local ad revenue growth."

"This thing is still one of the least expensive names you can find in the internet group," he said. "We like it on value, we like it on growth, we like it on the inflection point."

Investors can also look forward to growth in the retail and cloud industries, well illustrated by Amazon.

"You've got good premium growth you can probably bank on in both of those segments," said Mahaney.

However, he also said it's uncertain where the next big growth market will be.

"It could be devices, it could be groceries, heck, it could be these white-label services or products that they talked about this morning," he said.

"But at least in those core businesses, you should have premium growth parts. We think they're equally valuable to the company."