(ShareCast News) - Esure shares tumbled on Thursday following the completion of the demerger of price comparison website GoCompare.com.RBC Capital Markets downgraded its stance on the stock to 'underperform' from 'outperform' and slashed the price target to 180p from 305p as it removed GoCompare earnings from its forecasts."Whilst Esure should benefit from the current hardening seen in UK motor insurance, we expect the company to yield below the sub-sector average, a key reason to own a UK motor stock."The Canadian Bank argued that investors held Esure shares for two main reasons: its exposure to the upswing in UK motor insurance and to get exposure to GoCompare."With the demerger of GoCompare, and the subsequent realisation of some of its value, we see fewer obvious catalysts for the company to continue to re-rate."In a note at the end of October, RBC had said it expected Esure to initially trade at around 190p. However, it also said at the time that it valued the stock at 180p, which is a discount to peers."Due to a more mixed track record especially around capital returns, we value the esure business at a price-to-earnings multiple of 12.4x 2017E earnings, a small discount to UK motor peers of Direct Line and Hastings."At 1240 GMT, Esure shares were down 26% to 196.90p.