Is this your LAST chance to buy International Consolidated Airlns Grp SA plc, Berkeley Group Holdings plc and Standard Chartered plc before they soar?

After months of waiting (and plenty of propaganda), we've arrived at the referendum. While the polls seem split, the impact on share prices, particularly those of airlines, housebuilders and financials, has been indisputable. Given that a vote to remain could result in a massive shift in sentiment, is it worth buying shares in some of these companies before the result is announced?

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Ready to fly?

Shares in International Consolidated Airlines(LSE: IAG) have been losing height over the past six months, despite the company benefitting from the oil price wobble. Although the implications of a vote to leave the EU on this industry can only be estimated, it's possible that those wishing to travel to European destinations could see higher fares and fewer scheduled flights.

Trading on a price-to-earnings (P/E) ratio of under 6 for the current year, IAG may be considered a steal by some investors. The fact that the £11bn cap is now offering a well-covered yield of over 4% only makes it more attractive. A price-to-earnings growth ratio (PEG) of just 0.52 also suggests investors are getting a lot of growth for their cash.

That said, it's possible that we may have seen a top in the notoriously cyclical airline industry. Recent share price falls for IAG (and its peers) point to a market becoming increasingly wary of a gradual and sustained oil price recovery. A leave vote would further compound this negativity. Whether investors view the company as worthy of their capital might ultimately depend on how long they intend to hold its shares.

A play on the capital?

Berkeley Group(LSE: BKG) trades on a similarly low valuation to IAG at just under 9. It's not hard to see why the housebuilder has dipped. Its huge exposure to London makes it a fairly risky share to hold as we approach today's vote. Should we quit the EU, Berkeley's shares could suffer as the previously-buoyant market becomes less attractive to foreign investors.

Then again, it's equally reasonable to argue that the housing market won't suffer, whatever the referendum result. Whether investment comes from Europe or elsewhere, many will continue to be attracted to the lifestyle that comes with living in the UK (particularly London), relatively low crime levels and the quality of education on offer.

The chunky, well-covered forecast dividend yield of just under 6% is also attractive. Should earnings estimates not require adjusting after tomorrow, this should be comfortably above 6% in 2017. Factor-in the high operating margins and net cash position and Berkeley certainly has appeal.

Financial dog?

Shares in banks and insurers have been under pressure in the run-up to today's vote. Having said this, Standard Chartered(LSE: STAN) seems to have weathered the storm fairly well, possibly due to the company reporting a return to profit in April. Nevertheless, depressed commodity prices, weak emerging markets and the board's admission that group performance would "remain subdued in 2016" have all conspired to almost halve the share price since June last year.

Due to its vast international presence (particularly in Asia, the Middle East and Africa), I suspect the bank will be able to overcome any medium-term difficulties arising from a vote to leave the EU. However, a forward P/E of over 15 seems too high to me, given current market conditions. I think there a better opportunities elsewhere.

Ready to rocket?

All three companies have arguably suffered as a result of growing uncertainty over which way the UK will vote in today's referendum. In the case of IAG and Berkeley, the shares now look very cheap indeed.

While a vote to remain could see these shares soar by more than average as people flock back to firms they previously shunned. The question investors need to ask before buying is whether they can handle the equally possible scenario of a vote to leave the EU having an adverse impact on these companies, at least in the short-to-medium term. As always, it's vital to consider you own investing horizon, financial goals, required return and attitude to risk before making any kind of share purchase. If you're unsure as to whether to buy these companies now, it may be best to wait until after the result is announced.

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Paul Summers has no position in any shares mentioned. The Motley Fool UK has recommended Berkeley Group Holdings. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.