Reseller agreements typically allow companies to leverage external networks to sell their products, which can lead to increased sales and revenue. Given that this agreement is with Phalanx, it suggests a strategic move to enhance Arqit's distribution capabilities. This could be seen positively by investors, as it may lead to higher sales and greater market penetration for Arqit's encryption products. However, the actual impact on the stock will depend on the subsequent sales performance and market reception.