playing the stock market

[angliholic]

We buy lottery tickets, enter contests or spend hours building a business or playing the stock market. We're sure when we have plenty of money, we will be happy. But will we?

I doubt whether I can rewrite the underlined part as the following without making a change in meaning.
Moreover, I'm especially troubled by the phrase "playing the stock market." Is it right to utter "playing the stock" or "investing in the stock market?" Your advice? Thanks.

We buy lottery, take part in contests or spend hours setting up a business or investing the stock martet...

[Niall]

We buy lottery is not correct, we would usually say We play the lottery. Also, in this case we need to say investing in, as follows:
We play the lottery, take part in contests or spend hours setting up a business or investing in the stock market.

The lottery is a game and a competition: we can take part in it, and play it.
The stock market obviously isn't a game: we invest money in the stock market, or buy stocks. Playing the stock market is an idiom meaning investing in the stock market.

[angliholic]

Thanks, Niall, for the most desirable and transparent reply.
Got it.
By the way, what time is it in your place? Here it's 7:42 PM.

[Niall]

In the UK it is 11:45 (AM).
:)

[angliholic]

Thanks, Niall.
Then is it right to say "The time difference/leg/gap between us is about eight hours?"

[Niall]

The time difference/gap between us is about eight hours
Leg cannot be used in this sense.

[angliholic]

Thanks, Niall.
Got it.

[Anglika]

. Playing the stock market is an idiom meaning investing in the stock market.

I would argue that many who play the stock market may be investing, but they are also treating it as a gambling game at which they need to second-guess the market and its fluctuations, and risk losing in order to make bigger gains.

[Niall]

You could argue that. But I would argue the opposite purely out of personal experience of its use in the financial world (rather than for any grammatical reason).

[Anglika]

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