Bitcoin trading has gained popularity in Madagascar, including in the capital city of Antananarivo. Here are ten popular bitcoin trading platforms in Antananarivo, Madagascar:

1. LocalBitcoins: LocalBitcoins is a peer-to-peer bitcoin trading platform that allows users to buy and sell bitcoins directly with each other.

2. Binance: Binance is one of the largest cryptocurrency exchanges in the world, offering a wide range of trading pairs including bitcoin.

3. Luno: Luno is a user-friendly bitcoin exchange that allows users to buy, sell, and store bitcoins.

4. Paxful: Paxful is another peer-to-peer bitcoin trading platform that allows users to buy and sell bitcoins using various payment methods.

5. Coinmama: Coinmama is a popular platform for buying bitcoins with a credit or debit card, making it easy for users in Madagascar to purchase bitcoins.

6. Bitstamp: Bitstamp is one of the oldest cryptocurrency exchanges in the world, offering a secure platform for trading bitcoins.

7. Kraken: Kraken is a well-known cryptocurrency exchange that offers a wide range of trading pairs, including bitcoin.

8. eToro: eToro is a social trading platform that allows users to copy the trades of successful traders, making it a popular choice for beginners in Antananarivo.

9. CoinExchange: CoinExchange is a smaller cryptocurrency exchange that offers a variety of altcoins for trading, including bitcoin.

10. Gemini: Gemini is a regulated cryptocurrency exchange that offers a secure platform for trading bitcoins and other cryptocurrencies.

These are just a few of the popular bitcoin trading platforms available in Antananarivo, Madagascar. It is important for traders to do their own research and choose a platform that meets their specific needs and preferences.