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...

[Anglika]

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...

Take part or enter contests seem to me to be about equal.

"Playing the stock market" means that you are treating it like a gambling game - you are always assessing if you should buy or sell shares, aiming to make as much profit as you can, double-guessing what the market is about to do. It is a recognised idiom. Investing in the stock market is much too staid to replace it.

[angliholic]

Thanks, Anglika, for the helpful reply.
By the way, does "double-guessing" refer to "thinking over and over again?"

[Niall]

No, double-guessing refers to guessing, its like a reassured guess.

[angliholic]

Thanks, Niall.
Just to make sure, does "double-guessing" indicate "guessing again and again?"

[Niall]

No, not necessarily it means making a guess.

[angliholic]

Thanks, Niall.

But I still don't get it--if it's just making a guess, why it's "double-guessing?"
I suspect there must be more connotations attached to it than just making a guess?

[Niall]

No, I wouldn't say that there are any extra connotations associated with double-guessing.
I would say making a guess and double-guessing are synonyms.

[pennystocks]

Stock market is unstable in nature. Therefore, the price of penny stocks rises and falls every time. So it is difficult to decide what the next stocks to rise are. Analyzing of stock chart can be helpful. beststockreport.com

[Raymott]

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 in the stock martet...

As a very small-time home trader, I can tell you that share trading and investing are completely different. (They are referring to trading). Pennystocks is right. You evaluate the charts and make an educated decision about which stocks are going to move, and in which direction; then you buy and sell based on your analysis.
Some people call it gambling. If most of what we do in life involves a gamble, I'd agree. But gamblers shouldn't get better with experience and diligence.
But it is a type of playing. That doesn't mean it's easy though!

'Investing' is used for "Buy and Hold" buying, and that is not what the text means.