"Before hashrate marketplaces existed, attacking a cryptocurrency with 100,000 GPUs defending it more or less required owning 100,000 GPUs.
source https://www.google.com/url?rct=j&sa=t&url=https://www.finder.com.au/10-reasons-why-2019-is-the-year-of-the-cryptocurrency-51-attack&ct=ga&cd=CAIyGmM2Nzk3ODA2ZWViNjVjODI6Y29tOmVuOlVT&usg=AFQjCNFNS0M5bXYJuFxcHSbOb70R6Of8uw
