The current situation in clean energy stocks reminds several analysts of the dot-com boom in the late 1990s. According to data from Morningstar, global inflows into clean energy exchange-traded funds (ETFs) jumped to $14.7 billion in the six months to the end of March, up from only $1.3 billion in the same period a year…

Investors interested in renewable energy-related penny stocks often fit a certain profile. That is, they’re likely to be highly risk-tolerant, something that is essentially a necessity for these kinds of investments. The allure of penny stocks is their greater volatility versus higher-priced, more well-established equities. The outsized returns they can provide at a moment’s notice…