The answer is correct.
The value is a bit different from mine, but it's not important.

1) I think divided by 365 is a more common practice, like interest rate.
2) FYI, the theta become upper bound if it's an American option.

It's the first time I used this "giving coin away" post function.
Please let me know if you haven't got the coin.

Thanks again for interest in the question.

The value is not important compared to how to solve. I don't really mind about that.

Trader convention does not mean everything.

I remember Bloomberg and Reuters pricer give "original" theta value.
I forgot the 1-day value is divided by 250 or 360, though I think it's 365.

that's pure academic crap
if the number is wrong, it's wrong, you lose money, and your boss yells at you and you are fired, nobody cares how you solve it and why you get the  number wrong

7# oddsmaker

Thanks, for both the answer and the reward.

Thanks for your clarification. It's helpful.

But, if you feel bored or stupid to answer the question, get the f**king out of this BBS and mind your own shitty business. This BBS is manily for academic discussion.
Even if you're knowledgable, even if your are more experienced, even if what you say is the reallity, so WHAT?? Take off that show-off face. Gosh, I hate your attitude.

Why can't you treat people as equal? Helping others does not mean you have the privilege to pity on other people, dude. Otherwise, nothing you do will be appreciated. Don't understand why you do things to make people dislike you. If this makes you feel good, I guess you are the one to be pitied on.

移项以后加减变号都搞不清的人还有啥好说的

那又怎样？你就算看出来了一步移项变号的错误，有什么值得你这么拽的？！

水平牛不代表你人品好，就是看不惯你这种态度，嚣张什么啊？仗着年岁长点儿，有两年经验，有什么好炫耀的？

我相信坛子里比你牛的人有的是，即使没有，到你这岁数比你牛的人一定大有人在，第一次见到这么拽的。别在公司里受了鸟气就到坛子里发泄。

自重！

搞不懂瞎你激动啥，我好像没针对你吧，也就是说说你符号搞错而已，我觉得好笑的是楼主觉得无聊出个加减乘除的题，还煞有介事的什么难度1到2，结果拿个错的答案当个宝，最后还嘴硬说数字不重要过程才重要

是你瞎拽个啥，要写答案就写，别写完了还多嘴说真不知道自己为什么要回答这一题，这不毛病吗？搞什么飞机？这种居高临下的态度谁看了怕也会不爽吧，你要嫌楼主的题目简单，路过不就完了么，没谁请你答题，没必要写那样的回复。

论坛的目的是共同提高，不是显摆。错误是要纠正，但不是像你那样颐指气使，好像自己很了不起似的。每个人都有发表意见的权利，为什么别人的话你就认为是holy crap，你就认为没有意义？我没什么好激动的，就是有些事情如鲠在喉，不吐不快。你可以继续做你的“大牛”去了。

你在論壇的言論都足夠建立一個新 BS model 了.
當然要向你好好學習啦.


(這裏所指的 BS 不是 Black-Scholes)

大家火气都那么大哈.