Abstract—Obvious technological and economic advantages of High Voltage Direct Current (HVDC) systems over traditional High Voltage Alternating Current (HVAC) systems are becoming increasingly attractive for long-distance transmission. Several research papers on HVDC transmission networks have been published. However, most of them are focused on specific geographic locations or system components. Nonetheless, this study gives a brief yet thorough overview and international assessment of HVDC transmission systems. The following are the important points to be covered in the paper: The state of the art of HVDC technology development, the benefits, economic comparisons, and constraints of HVDC systems, as well as the size of the international HVDC industry market and the impact of COVID-19 on the market, are all explored in-depth, along with a mathematical model for forecasting the evolution of market demand. According to market statistics, the Asia-Pacific region (APAC) is the biggest market and technical leader in HVDC technologies. In addition, the market for HVDC will continue to grow in the forecasted period.