Detection of financial bubbles in cryptocurrency prices

While blockchain technology offers various usage areas in the field of economy, prominent cryptocurrencies continue their search for value and price. Since the second quarter of 2017, collapses and similar signals that have emerged in crypto money prices and its continuation have started to be seen again in the first quarter of 2019. In this study, Bitcoin (BTC), which has a large transaction volume in the market and the first crypto currency, Ethereum (ETH), which has the largest market value after Bitcoin, Cardano (ADA), which aims to run a public blockchain platform for smart contracts, Bitcoin Cash (BCH), a fork and altcoin of Bitcoin, Litecoin (LTC), the first altcoin, Ripple (XRP), which plays an important role in sending money via the Internet, an open-source distributed ledger and cryptocurrency (IOTA) designed for the Internet of Things, and The existence of speculative bubbles of cryptocurrencies such as Stellar (XLM), which is used as a payment method, has been tested with Generalized Sup Augmented Dickey Fuller (GSDAF) methods. The results show that the price bubbles formed between 2020-2021 are open to speculative movements.