  The Ethereum blockchain and its ERC20 token standard have revolutionized the
landscape of digital assets and decentralized applications. ERC20 tokens
developed on the Ethereum blockchain have gained significant attention since
their introduction. They are programmable and interoperable tokens, enabling
various applications and token economies. Transaction graphs, representing the
flow of the value between wallets within the Ethereum network, have played a
crucial role in understanding the system's dynamics, such as token transfers
and the behavior of traders. Here, we explore the evolution of daily
transaction graphs of ERC20 token transactions, which sheds light on the
trader's behavior during the Black Swan Events -- 2018 crypto crash and the
COVID-19 pandemic. By using the tools from network science and differential
geometry, we analyze 0.98 billion of ERC20 token transaction data from November
2015 to January 2023. Our analysis reveals that ERC20 financial ecosystem has
evolved from a localized wealth formation period to a more mature financial
ecosystem where wealth has dispersed among the traders in the network after the
crypto crash and during the pandemic period. Before the crash, most sellers
only sell the tokens, and buyers only buy the tokens. However, after the crash
and during the pandemic period, sellers and buyers both performed buying and
selling activities. In addition, we observe no significant negative impact of
the COVID-19 pandemic on user behavior in the financial ecosystem.
