Investing and trading giant IG is turning heads with an enticing 8.5% AER (annual equivalent rate) cash interest rate offer-a figure that's doubling the current Bank of England base rate.

This lucrative interest rate is on the table for individuals who set up a stocks and shares ISA, Sipp (self-invested personal pension), or a general investment account (GIA) with an initial deposit before the deadline on May 31.

After making their first investment, qualifying clients who deposit additional funds can enjoy an 8.5% interest yield on uncleared cash resting in their accounts until August 31, as long as they maintain any investment position during the same timeframe.

Post-August 31, interest will revert to a standard 4.25% with IG, which does not provide a specialised cash savings account. Hence, the higher interest would be applicable to cash not invested within its ISAs, Sipps, or GIAs, with interest being paid on cash balances capped at £100,000.

IG's UK managing director, Michael Healy, said: "Many investors are sitting on the sidelines right now as they wait for market clarity - this offer gives them a place to park their money and still earn a serious return."

Existing account holders have a chance to benefit from the offer too, as long as they haven't made their first trade yet and do so before May 31. This opportunity comes hot on the heels of the Bank of England's base rate cut from 4.5% to 4.25%, sparking speculation that savings providers might reduce their interest rates.

The financial markets have been experiencing turbulence lately, partly due to global economic and political uncertainties, including concerns about US tariffs.

Finance expert Rachel Springall from Moneyfactscompare.co.uk said: "The high interest rate looks enticing, and it is positive to see appetite to draw in savers who are looking to make their money work harder for them. However, it is essential savers carefully check the terms and conditions of the account before they invest.

"Savers need to understand that the interest rate is applied to money sitting in a specific type of account, which should entice investors who are waiting for the market storm to calm. Offering a high interest rate is a great way to entice the more risk-averse saver, and it gives them an opportunity to consider the longer-term benefits of investing in the stock market once they feel comfortable to do so.

"In the meantime, they can earn an attractive rate on their hard-earned cash, but they need to make sure they review it once the offer expires. Investing puts any capital at risk, so this option will not be suitable for every saver."

West Brom Building Society has delivered a welcome lift to savers by announcing a rate hike on its Four Access Saver account last Friday, with the interest rate jumping from 4.40% to an enticing 4.65% AER (variable).

Customers both new and longstanding, who hold issues one and two of the product, will benefit from the improved rate, as confirmed by the Society. The application process is accessible online, with the added flexibility of making up to four withdrawals annually.

Sophie Dwyer, the building society's product manager, said: "As a mutual, our customers are at the heart of everything we do."