The 5 April deadline for using this year’s Stocks and Shares ISA allowance is looming fast. It’s just over three weeks away.

For investors with money to spare, using the £20,000 allowance is usually a no-brainer. Every penny invested is free of capital gains tax, dividend tax, and income tax for life. But many understandably feel nervous right now. Who wants to put money into the stock market while drones and missiles shake the Middle East?

Please note that tax treatment depends on the individual circumstances of each client and may be subject to change in future. The content in this article is provided for information purposes only. It is not intended to be, neither does it constitute, any form of tax advice. Readers are responsible for carrying out their own due diligence and for obtaining professional advice before making any investment decisions.

It certainly takes strong nerves but there is an easy compromise. Most ISA platforms allow investors to use their allowance without investing straight away. They can simply leave the money sitting in cash within the ISA platform’s trading account, waiting for calmer conditions before buying shares.

Time to get investing

That’s a useful option for anyone wary of jumping into the market right now. At The Motley Fool, though, we take a different view. Typically, we see a market dip as a good time to buy shares, as valuations are typically lower and dividend yields higher. Waiting for volatility to pass can easily backfire, because by the time the outlook clears, many shares have already rebounded.

So, yes, it’s a good time, but there are risks. Unless the Iran conflict wraps up quickly, shares could fall further. Nobody knows what will happen. So my strategy is simple. First, use the ISA allowance before the deadline. Second, start feeding money gradually into shares, taking advantage of market dips. But keep some cash in reserve in case prices fall further.

Investors also need a reality check. Timing the exact bottom of the market is almost impossible. Perfection simply isn’t achievable.

One more thing. In our view, investors should only buy shares with the aim of holding them for at least five years. That gives them to recover from short-term shocks and allow dividends and share prices to compound. Markets are constantly hit by volatility, yet history shows they recover once the outlook becomes clearer.

Is Barratt Redrow a bargain?

The bigger question is which shares to buy. FTSE 100-listed easyJet, Persimmon, Diageo, and Hikma Pharmaceuticals have all dropped more than 20% in the past month. Housebuilder Barratt Redrow (LSE: BTRW) is down 27%.

The war hasn’t helped sentiment, but the construction sector was already struggling. Housebuilders have endured years of setbacks, including Brexit, the pandemic, rising inflation and mortgage rates, and the scrapping of the Help to Buy scheme. Investors were hoping for relief this year, with inflation expected to fall. The latest geopolitical turmoil has cast doubt on that.

Ironically, that’s also what makes Barratt Redrow look interesting. The shares now trade on a tempting price-to-earnings ratio of roughly 11, while the dividend yield has climbed above 6%.

It’s not without risk. If oil prices stay high, the UK economy could tip into recession. Mortgage rates are already edging up, adding to buyer wariness. Drip-feeding money into the market can help spread the risk, and I think this is one to consider. Plenty of other FTSE 100 stocks look tempting but, as ever, buying with a long-term view is a good idea.