Last Twelve Months - LTM
See: Trailing Earnings. Investors ask, "What multiple of earnings is the stock trading at...and don't correct our dangling participle grammar." They say that. Really. Then companies reply, "Multiple of what year's earnings? Based on our projections, we trade at only 4 times our earnings 5 years from now." And investors reply, "No, when we ask about the current multiple, we mean the trailing multiple of the last 12 months or the last 4 quarters and the question applies to all metrics as they trail for a year..." So that's the context of LTM, bad grammar aside.