Apple investors could be excused for feeling on top of the world. Another blowout quarter has sent the stock booming to another all-time high. The iPad seems to be a success. Everything the company touches seems to turn to gold.

Savor the moment, by all means. But don't get complacent. If you're an Apple shareholder, here are seven things to be concerned about-and one thing you can do about it.

1. Apple's good-but not that good. It's just that the competition is so bad. Nokia, Microsoft, Samsung, Palm: From smartphones to Internet tablets to computers, it's hard to believe so many big companies have blown it so badly. And they've committed mainly unforced errors, such as terrible user interfaces. I bought a non-iPod MP3 player the other day. It's great ... except making playlists is nearly impossible.

As long as the competition acts like this, Apple will keep winning. But its success owes less to the genius of Apple than the incompetence of everyone else. And that's something you can't control.

2. Apple fatigue. Was anything so ridiculous as the coverage of the new iPad? A computer company launched a new computer. Time and Newsweek put it on the cover, for heaven's sake, complete with fawning copy from the likes of Stephen Fry. A lot of people are getting absolutely fed up with this circus. Fashions come, but fashions go. Is Apple becoming overexposed? Right now Steve Jobs could sell his old underwear for $200 a pair (the 'iPants'), and the sheep would line up at your local Apple store. If this mania lasts, it will be a first in human history.

3. The share price. At $260, Apple's stock price has more than doubled in a year. Amateur investors say, 'It's going up.' Present tense. Serious investors say, more accurately: 'It has gone up.' Past tense. No one knows the future. And the more it rises, the less attractive it gets. It's now 20 times annual cash flow and 5 and a half times annual sales. At $235 billion, the company is being valued at more than Sony, Research In Motion, Dell, Motorola, Nokia, HTC, SanDisk and Palm ... put together. That assumes a lot.

4. Steve Jobs's ego. I don't care how much of a genius he is: Nobody is perfect. Yet Mr. Jobs has been subject to extravagant cheerleading, and it's not as if he was overendowed with a sense of humility to begin with. Bottom line: If and when he makes mistakes, who is going to stop him? A small but telling example: One thing keeping Apple from lots of extra iPhone sales to business users is that Mr. Jobs, for some reason, has a thing against keyboards. There's no business reason for it. It's a silly, unforced error.

5. The cellular networks. At what point will they stop giving away the store? Right now they're paying most of the cost of each new iPhone, and under-charging for the data plans too. That's great for customers and great for Apple, and bad for the networks. The iPhone is an expensive data hog that soaks up airtime, and there's always a risk the networks will start playing tougher. Verizon, which lost out to AT&T three years ago for the right to carry the iPhone in the US, doesn't seem to be suffering as a result. Its investors have done no worse than those of AT&T. And its data traffic just jumped 20%, even without the Apple phone.

6. Apple backlash. As the competition forfeits game after game, Apple is starting to dominate industries from cell phones and games to music and media. Now it looks like it wants to dominate ebooks too. But if Ken Auletta's account in the latest New Yorker is correct, Apple's game plan to defeat Amazon means teaming up with book publishers-and that may mean higher book prices for consumers. How will consumers react? And what will that do for Apple's 'friendly,' rebel image? Anyway, you can't play the underdog when you're the third-biggest company in the world by market value. Apple is already worth more than General Electric, Wal-Mart, Chevron or Procter & Gamble. It is worth nearly as much as Microsoft. At some point it starts to look like the Big Brother it once vilified. It may even look like the new Microsoft.

7. Steve Jobs's health. This is the 'ick' issue. But Apple cheerleaders can't have it both ways. They can't hail Steve Jobs as a visionary genius and the world's greatest CEO, and then say it's none of shareholders' business whether he will still be running the company in three years' time. It's only a year since he had a liver transplant, and investors can hardly feel confident they got all the relevant information clearly and early. We all hope Mr. Jobs enjoys the best of health and lives to a ripe old age. But he still looks worryingly thin. This is something for investors to keep an eye on.

Some of these are issues that could erupt into problems quickly. Others, if they do emerge, would take more time. But if you're a nervous Apple investor, what are your alternatives? Sure you could sell some stock and take your profits. But if you don't want to get off this train quite yet, here's another idea: You could buy some insurance using 'put' options. These pay out if the stock falls. So for $19 you can buy $200 puts, good until January 2012. These will limit your downside on the stock to $200. But if Apple keeps booming upwards, all you can lose is the $19.

Brett Arends

• competition [,kɔmpi´tiʃən] n.比赛；竞争 (初中词汇)
• mainly [´meinli] ad.主要地；大体上 (初中词汇)
• player [´pleiə] n.游戏的人；选手 (初中词汇)
• genius [´dʒi:niəs] n.天才(人物)；天赋 (初中词汇)
• everyone [´evriwʌn] pron.=everybody 每人 (初中词汇)
• computer [kəm´pju:tə] n.计算机；电子计算器 (初中词汇)
• absolutely [´æbsəlu:tli] ad.绝对地；确实 (初中词汇)
• amateur [´æmətə, ,æmə´tə:] n.业余爱好者 (初中词汇)
• attractive [ə´træktiv] a.有吸引力；诱人的 (初中词汇)
• annual [´ænjuəl] a.每年的 n.年刊 (初中词汇)
• research [ri´sə:tʃ] n.&vi.调查；探究；研究 (初中词汇)
• expensive [ik´spensiv] a.费钱的，昂贵的 (初中词汇)
• suffering [´sʌfəriŋ] n.痛苦；灾害 (初中词汇)
• traffic [´træfik] n.交通，运输 (初中词汇)
• account [ə´kaunt] vi.说明 vt.认为 n.帐目 (初中词汇)
• running [´rʌniŋ] a.奔跑的；流动的 (初中词汇)
• emerge [i´mə:dʒ] vi.出现；显露；暴露 (初中词汇)
• nervous [´nə:vəs] a.神经的；神经过敏的 (初中词汇)
• concerned [kən´sə:nd] a.有关的；担心的 (高中词汇)
• fatigue [fə´ti:g] n.&vt.(使)疲劳(劳累) (高中词汇)
• ridiculous [ri´dikjuləs] a.荒谬的；可笑的 (高中词汇)
• circus [´sə:kəs] n.马戏(团)；圆形广场 (高中词汇)
• billion [´biljən] num.万亿 (高中词汇)
• motion [´məuʃən] n.手势 vt.打手势 (高中词汇)
• extravagant [ik´strævəgənt] a.奢侈的；过度的 (高中词汇)
• dominate [´dɔmineit] v.统治；控制；俯视 (高中词汇)
• gamble [´gæmbəl] v.&n.赌博；投机；冒险 (高中词汇)
• confident [´kɔnfidənt] a.有信心的，自信的 (高中词汇)
• relevant [´relivənt] a.有关的；中肯的 (高中词汇)
• winning [´winiŋ] n.&a.胜利(的) (四级词汇)
• accurately [´ækjuritli] ad.准确地；精密地 (四级词汇)
• humility [hju:´militi] n.谦逊，谦让 (四级词汇)
• amazon [´æməzən] n.女战士 (四级词汇)
• upwards [´ʌpwədz] ad.=upward (四级词汇)
• underwear [´ʌndəweə] n.内衣；衬衣 (六级词汇)
• transplant [træns´plɑ:nt, -plænt] vt.移植(种)；迁移 (六级词汇)
• investor [in´vestə] n.投资者 (六级词汇)