Uncertainty has ruled the markets since last week’s EU referendum vote. If there’s one thing investors hate, it’s uncertainty and plunging markets have reflected this in the past three or four days.

For astute long-term Foolish investors, however, the last week’s market panic has thrown up some great opportunities.

Take Sky (LSE: SKY) for example. The company is unlike to be significantly affected by the outcome of the referendum. The group has operations in the UK, Italy, and Germany all of which reported strong customer and profits growth during the third quarter of the company’s financial year (calendar Q1). The group’s German division, Sky Deutschland reported its first ever operating profit, while Sky’s Italian division achieved the highest quarterly customer growth in four years.

Meanwhile, here in the UK, the company continues to grow and improve its offering for customers. Cash flows are locked-in with contracts that span 12 months or more, and unless there’s a serious consumer recession, the demand for Sky’s services is likely to remain robust for the foreseeable future.

Sky’s earnings per share are expected to jump by 10% this year. Based on these forecasts the company is trading at a forward PE of 13.7 and the shares support a dividend yield of 4%.

Dominates the market 

BT (LSE: BT.A) has many of the same defensive qualities as Sky, but the company also owns and manages Britain’s telecommunications infrastructure, making it an extremely defensive company.

BT is unlikely to see its revenues evaporate overnight. Even in recessions people still need telecommunication services, so if the worst should happen and the UK plunges into a deep economic crisis, BT should come out on top. Indeed, during the financial crisis between 2008 and 2010, the company’s operating income fell by only 9.8% before rebounding in 2011. Between 2008 and year-end 2012 BT’s operating income had increased by 24%.

And after recent declines, shares in the company are currently trading at a forward P/E of 13.9 and support a dividend yield of 3.8%. City analysts expect the company to report earnings per share growth of 8% next year.

Strong growth, panic selling

Shares in ITV (LSE: ITV) have lost around a fifth of their value over the past five days extending year-to-date losses. Since the beginning of the year, ITV’s market value has fallen by nearly 40% on concerns about the state of the advertising market. 

However, while many investors perceive ITV to be nothing but a television channel, the group has many strings to its bow. In the company’s Q1 trading update, it reported a 14% year-on-year increase in revenue, led by a 44% jump in revenue from ITV Studios, the group’s production arm. Online Pay & Interactive revenue also registered a high-double-digit increase of 17%.

ITV has a history of returning any excess cash to investors via special dividends and now looks to be a great time for investors to get in on the company’s lucrative cash return strategy. Since the end of 2012 the company has returned 41p per share to investors, around 25% of the current share price.

Shares in ITV currently trade at a forward P/E of 11.9 and support a regular dividend yield of 3.6%.

The worst mistake you could make

According to a study conducted by financial research firm DALBAR, the average investor realised an average annual return of only 3.7% a year over past three decades, underperforming the wider market by around 5.3% annually.

This underperformance can be traced back to several key mistakes that all investors make. To help you realise and understand the most common mis-steps, the Motley Fool has put together this new free report entitled The Worst Mistakes Investors Make.

The report is a collection of Foolish wisdom, which should help you avoid needlessly losing too many more profits. Click here to download your copy today.

Rupert Hargreaves owns shares of Sky. The Motley Fool UK has recommended ITV and Sky. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.