Proof-of-Stake (PoS) cryptocurrencies Cardano (CRYPTO: ADA) and Polygon (CRYPTO: MATIC) saw a major price growth following recent news that Tesla Inc. (NASDAQ: TSLA) CEO Elon Musk is looking for an energy-efficient alternative to Bitcoin (CRYPTO: BTC). What Happened: Polygon saw its price increase by about 40% from a 24-hour low of $1.343 to a high…