Research in olefin metathesis has continued unabated since the 1970s, with remarkable advancements coming after the development of well-defined catalysts based on molybdenum, tungsten, and ruthenium. Although many significant achievements have been made in this field, there still remains much room for growth. This talk will disclose two such advancements. In the first example, ring-opening metathesis polymerization (ROMP) of 1-alkyl-trans-cyclooctenes has been performed, yielding precursors to precision short-chain branched polyethylene. Mechanistic investigations, and their implications for polymer molar mass, will be presented. In the second case, cross-metathesis with catalysts based on abundant and inexpensive vanadium has been achieved. Mechanistic investigations into catalyst decomposition will be discussed, which provide valuable insight for future catalyst design.