Already hurting because of low oil prices, Canadian oil and gas companies are being hit hard on the stock market.

In early trading on Monday, the price of some stocks hit levels not seen in 15 years. Stock markets around the globe suffered huge losses, although some were able to rebound.

Calgary-based oil and gas company Encana had its shares dip to $7.44, their lowest level since the company was created through a merger in 2002.

At one point, Canadian Oil Sands had its stock fall to $5.61, a price not seen since 2001.

This ranks near the top in corrections. - Rafi Tahmazian, Canoe Financial

"It's a complete washout," said Sheryl Purdy, a stock broker with Leede Financial Markets in Calgary. "The markets are trading so low."

Purdy suggests some investors are terrified and nervous as oil prices keep falling. The price of the main North American oil benchmark known as West Texas Intermediate (WTI) dropped again on Monday, trading just above the $38 US a barrel level for much of the day.

"I think it spooked the market with West Texas breaking $40. A lot of people had in their mind 'just don't break $40, just don't break $40,'" said Purdy.

Oil prices have yet to recover since they began to plunge more than a year ago from prices about $100 a barrel. There continues to be an oversupply of oil, which is driving prices down.

"This ranks near the top in corrections," said Rafi Tahmazian, a fund manager with Canoe Financial in Calgary.

Energy markets have traditionally been a volatile investment and the recent fluctuations are reinforcing that notion.

Canadian energy stocks could continue to slide, according to Martin Pelletier with TriVest Wealth Counsel. (CBC) "I don't think we've seen the full impact of low oil prices," said Martin Pelletier, a portfolio manager with TriVest Wealth Counsel in Calgary. "Remember 2008 and 2009? It was pretty bad here in town and we are nowhere near that, and yet oil prices are testing those levels again."

A drop in stock prices is concerning for oil and gas companies because it can affect cash flow and the ability to pay off debt.

"Oil and gas equities are riding the roller-coaster downhill just like everything else," said Judith Dwarkin, an energy economist with ITG Investment Research in Calgary. "In the past year, we've seen weak commodity prices, especially on the oil side. This is adding more pain to the mix."

Canadian energy stocks have had a rough ride for much of 2015. So far this year, the stock price for Cenovus Energy is down 31 per cent, Imperial Oil is down 12 per cent and Suncor is down nine per cent.