Hexagram 1, Qián (The Creative): Line 6 (top)
乾卦上九 · 乾为天 · 中文版
上九：亢龙有悔。
The line (Legge)
In the sixth (or topmost) NINE, undivided, (we see its subject as) the dragon exceeding the proper limits. There will be occasion for repentance.
Small Image commentary
'The dragon exceeds the proper limits; - there will be occasion for repentance:' - a state of fulness, that is, should not be indulged in long.
象曰：亢龙有悔，盈不可久也。
In plain words
The dragon that has flown too high will have cause for regret. The top line is the highest point of the hexagram, where yang strength reaches its limit. The Small Image says that fullness cannot last. The Wenyan commentary describes it as knowing how to advance but not how to withdraw.
Applying it to your situation
If you feel you have everything under control, this line is a reminder to leave yourself room to turn: don't say everything, don't push everything to the end. If you were to step back half a pace now, what would that step be?
Position
A solid (yang) line in the top place, which is a yin (even) place, so it is not in its proper place. Its partner is line 3; both are yang, so they do not respond.
If this line moves
With this line moving alone, Qián changes into Hexagram 43 Guài (Breakthrough). The Jiaoshi Yilin verse for this change (Chinese): 焦氏易林·乾之夬.
The hexagram
Hexagram 1 Qián (The Creative). The Judgment: Qian (represents) what is great and originating, penetrating, advantageous, correct and firm.
Previous: Line 5 · Next: All lines nine
English text: James Legge, The Yi King (Sacred Books of the East, vol. 16, 1882), public domain, as transcribed by the Chinese Text Project. Chinese: the received text. Offered for study and reflection, not as prediction. Plain-English readings and position notes by this site.