The Eleventh Circuit held that a securities underwriter’s four prior lawsuits against a co-underwriter did not waive the underwriter’s right to arbitration because the prior suits were insubstantial.  Grigsby & Associates, Inc. v. M Securities Inv., No. 13-15208 (11th Cir. Dec. 28, 2015).  The co-underwriter had not been served with three of the suits, and the fourth suit was dismissed for want of prosecution.  Moreover, the underwriter’s ten-year delay in demanding arbitration was not a sufficient basis for finding waiver absent other substantial conduct inconsistent with an intent to arbitrate or a showing that the co-underwriter had sustained prejudice.