How worried should we be about tumbling stock markets?

As stock markets continue to tumble after the US imposition of sweeping and swingeing tariffs, many are asking does this qualify as a stock market “crash” and what that could mean for them.
The word crash has been used sparingly over the decades and is usually reserved for a fall of over 20% from a recent peak in a day, or over the course of a couple of days.
On 19 October, 1987 – also known as Black Monday – the US stock market lost 23% of its value in a single day, and other stock markets had similar falls. The UK FTSE index fell 23% over two days – partly because it closes earlier than New York, and so it often plays catch up with whatever happens in the US the next morning.
That was most definitely a crash.
In 1929, the US stock market lost over 20% of its value in two days – and 50% within three weeks. That was the famous Wall Street Crash that ushered in the great depression of the 1930s.

Courtesy: BBC