Why not put everything in one stock

The platform caps a single order at 20% of your portfolio. That is not to annoy you.

Diversification With 5 stocks from different sectors (banks, real estate, food, telecom, industry), bad news in one sector does not break the whole portfolio.

Weight Check your profile page: the allocation shows what percent each stock takes. Above 30% in one name means you are too concentrated.

The index as a benchmark Compare yourself with EGX30 on the performance page. If you do not beat it over a long period, index funds are a sensible alternative.