He said he could affect the stock market in ways that can't be easily proven.

他说他可以以不易察觉的手段影响股市行情。

That's a lot of bull.Everyone knows he has been broken.

那都是胡说八道。所有人都知道他已经破产了。

You must do it because I said so.

你必须这么干，因为我说了算。

That's a lot of bull.You can't tell me what to do.

胡扯，你没资格给我发号施令。

重点讲解

You are speaking nonsense.

That's a lot of bull.

Bull在这句话中是bullshit（牛粪）的缩写，在这里指“毫无价值的论调和观点”。也可以直接说:You're talking bullshit.（你就是在扯淡）。但这个说法有点粗鲁，仅限于非常生气的情况下使用。