Buying cryptocurrencies depends on your strategy and investment goals, but here are some general rules that may help you:

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1. Buy the Dip

Buy when the currency is significantly declining after a period of stability or growth.

Make sure that the decline is due to temporary factors and not fundamental problems in the project.

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2. At the beginning of an upward trend

Use technical analysis to determine when the currency is starting to move from a downward trend to an upward trend.

Look for signals such as moving averages crossing or resistance levels breaking.

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3. Long-term Investment

If you believe in a particular project (such as Polkadot or Cardano) and see it as having a promising future, you can buy the currency regardless of the current price.

Focus on projects that solve real problems and have a strong development team.

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4. When technical updates or partnerships are announced

Cryptocurrencies often rise in value when important developments are announced. Follow the news and updates about the currencies you follow.

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5. In quiet market periods

Try to avoid buying when the market is in a bubble state where prices are rising very quickly.

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6. Build a gradual buying strategy (Dollar-Cost Averaging)

Instead of buying the entire amount at once, divide your investment into several installments over time.

This method reduces the impact of price fluctuations.