Shares of Diffusion Engineers Limited hit a 5% upper circuit at ₹207.2 on Monday, following significant purchases by domestic investors 3P India Equity Fund 1 and Trade Corner, who bought nearly 11 lakh shares and 3.69 lakh shares at average prices of ₹202.76 and ₹193.5, respectively. The total deal value amounted to ₹29.5 crore.