Bitcoin Gold is labeled by many as the most disappointing fork of Bitcoin, both in terms of the coin's fundamental value and its historical price action. Fundamentally, the difference between the original ecosystem lies in the use of the Equihash 144,5 mining algorithm, also known as Zhash, which allows the use of graphic cards for the purpose of mining, thus making the process of acquiring BTG somewhat more accessible. However, Bitcoin Gold is inherently more vulnerable than its forefather because there have been as many as three instances of successful 51% attack on the BTG network, the latest of which occurred this January.
Perhaps that is the primary reason why the general interest towards this coin has completely degraded, as it becomes evident from this all-time price chart.
All-time Bitcoin Gold price action chart