The antonyms for the phrase "runs low" are "runs high" or "overflows." During a drought, water in a reservoir runs low, but after a heavy rain, it runs high. Similarly, when the gas in your car's tank runs low, you need to refill it. Conversely, when the stock market runs low, it causes anxiety among investors, but a bull market trend describes a situation in which shares run high. Finally, when your patience or tolerance runs low, it's easy to get frustrated, but when it runs high, you may be able to handle difficult situations better.